diff --git a/Modules/_io/clinic/_iomodule.c.h b/Modules/_io/clinic/_iomodule.c.h
index 112408a95df..68a8a205140 100644
--- a/Modules/_io/clinic/_iomodule.c.h
+++ b/Modules/_io/clinic/_iomodule.c.h
@@ -188,15 +188,10 @@ _io_open(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kw
             _PyArg_BadArgument("open", "argument 'mode'", "str", args[1]);
             goto exit;
         }
-        Py_ssize_t mode_length;
-        mode = PyUnicode_AsUTF8AndSize(args[1], &mode_length);
+        mode = PyUnicode_AsUTF8(args[1]);
         if (mode == NULL) {
             goto exit;
         }
-        if (strlen(mode) != (size_t)mode_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -215,15 +210,10 @@ _io_open(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kw
             encoding = NULL;
         }
         else if (PyUnicode_Check(args[3])) {
-            Py_ssize_t encoding_length;
-            encoding = PyUnicode_AsUTF8AndSize(args[3], &encoding_length);
+            encoding = PyUnicode_AsUTF8(args[3]);
             if (encoding == NULL) {
                 goto exit;
             }
-            if (strlen(encoding) != (size_t)encoding_length) {
-                PyErr_SetString(PyExc_ValueError, "embedded null character");
-                goto exit;
-            }
         }
         else {
             _PyArg_BadArgument("open", "argument 'encoding'", "str or None", args[3]);
@@ -238,15 +228,10 @@ _io_open(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kw
             errors = NULL;
         }
         else if (PyUnicode_Check(args[4])) {
-            Py_ssize_t errors_length;
-            errors = PyUnicode_AsUTF8AndSize(args[4], &errors_length);
+            errors = PyUnicode_AsUTF8(args[4]);
             if (errors == NULL) {
                 goto exit;
             }
-            if (strlen(errors) != (size_t)errors_length) {
-                PyErr_SetString(PyExc_ValueError, "embedded null character");
-                goto exit;
-            }
         }
         else {
             _PyArg_BadArgument("open", "argument 'errors'", "str or None", args[4]);
@@ -261,15 +246,10 @@ _io_open(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kw
             newline = NULL;
         }
         else if (PyUnicode_Check(args[5])) {
-            Py_ssize_t newline_length;
-            newline = PyUnicode_AsUTF8AndSize(args[5], &newline_length);
+            newline = PyUnicode_AsUTF8(args[5]);
             if (newline == NULL) {
                 goto exit;
             }
-            if (strlen(newline) != (size_t)newline_length) {
-                PyErr_SetString(PyExc_ValueError, "embedded null character");
-                goto exit;
-            }
         }
         else {
             _PyArg_BadArgument("open", "argument 'newline'", "str or None", args[5]);
@@ -404,4 +384,4 @@ _io_open_code(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObjec
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=5d60f4e778a600a4 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=feb173d5f2bfb98a input=a9049054013a1b77]*/
diff --git a/Modules/_io/clinic/fileio.c.h b/Modules/_io/clinic/fileio.c.h
index cf3ba28b066..6f5d660affd 100644
--- a/Modules/_io/clinic/fileio.c.h
+++ b/Modules/_io/clinic/fileio.c.h
@@ -107,15 +107,10 @@ _io_FileIO___init__(PyObject *self, PyObject *args, PyObject *kwargs)
             _PyArg_BadArgument("FileIO", "argument 'mode'", "str", fastargs[1]);
             goto exit;
         }
-        Py_ssize_t mode_length;
-        mode = PyUnicode_AsUTF8AndSize(fastargs[1], &mode_length);
+        mode = PyUnicode_AsUTF8(fastargs[1]);
         if (mode == NULL) {
             goto exit;
         }
-        if (strlen(mode) != (size_t)mode_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -528,4 +523,4 @@ _io_FileIO_isatty(fileio *self, PyObject *Py_UNUSED(ignored))
 #ifndef _IO_FILEIO_TRUNCATE_METHODDEF
     #define _IO_FILEIO_TRUNCATE_METHODDEF
 #endif /* !defined(_IO_FILEIO_TRUNCATE_METHODDEF) */
-/*[clinic end generated code: output=1c0f4a36f76b0c6a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=27cff9d0a618edb6 input=a9049054013a1b77]*/
diff --git a/Modules/_io/clinic/textio.c.h b/Modules/_io/clinic/textio.c.h
index b24a1669f9b..25c301ecdb6 100644
--- a/Modules/_io/clinic/textio.c.h
+++ b/Modules/_io/clinic/textio.c.h
@@ -185,15 +185,10 @@ _io__TextIOBase_write(PyObject *self, PyTypeObject *cls, PyObject *const *args,
         _PyArg_BadArgument("write", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t s_length;
-    s = PyUnicode_AsUTF8AndSize(args[0], &s_length);
+    s = PyUnicode_AsUTF8(args[0]);
     if (s == NULL) {
         goto exit;
     }
-    if (strlen(s) != (size_t)s_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _io__TextIOBase_write_impl(self, cls, s);
 
 exit:
@@ -475,15 +470,10 @@ _io_TextIOWrapper___init__(PyObject *self, PyObject *args, PyObject *kwargs)
             encoding = NULL;
         }
         else if (PyUnicode_Check(fastargs[1])) {
-            Py_ssize_t encoding_length;
-            encoding = PyUnicode_AsUTF8AndSize(fastargs[1], &encoding_length);
+            encoding = PyUnicode_AsUTF8(fastargs[1]);
             if (encoding == NULL) {
                 goto exit;
             }
-            if (strlen(encoding) != (size_t)encoding_length) {
-                PyErr_SetString(PyExc_ValueError, "embedded null character");
-                goto exit;
-            }
         }
         else {
             _PyArg_BadArgument("TextIOWrapper", "argument 'encoding'", "str or None", fastargs[1]);
@@ -504,15 +494,10 @@ _io_TextIOWrapper___init__(PyObject *self, PyObject *args, PyObject *kwargs)
             newline = NULL;
         }
         else if (PyUnicode_Check(fastargs[3])) {
-            Py_ssize_t newline_length;
-            newline = PyUnicode_AsUTF8AndSize(fastargs[3], &newline_length);
+            newline = PyUnicode_AsUTF8(fastargs[3]);
             if (newline == NULL) {
                 goto exit;
             }
-            if (strlen(newline) != (size_t)newline_length) {
-                PyErr_SetString(PyExc_ValueError, "embedded null character");
-                goto exit;
-            }
         }
         else {
             _PyArg_BadArgument("TextIOWrapper", "argument 'newline'", "str or None", fastargs[3]);
@@ -980,4 +965,4 @@ _io_TextIOWrapper_close(textio *self, PyObject *Py_UNUSED(ignored))
 {
     return _io_TextIOWrapper_close_impl(self);
 }
-/*[clinic end generated code: output=e58ce89b7354e77a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=c9ffb48a5278cbd4 input=a9049054013a1b77]*/
diff --git a/Modules/_io/clinic/winconsoleio.c.h b/Modules/_io/clinic/winconsoleio.c.h
index 6cab295c446..8609fc9ede9 100644
--- a/Modules/_io/clinic/winconsoleio.c.h
+++ b/Modules/_io/clinic/winconsoleio.c.h
@@ -106,15 +106,10 @@ _io__WindowsConsoleIO___init__(PyObject *self, PyObject *args, PyObject *kwargs)
             _PyArg_BadArgument("_WindowsConsoleIO", "argument 'mode'", "str", fastargs[1]);
             goto exit;
         }
-        Py_ssize_t mode_length;
-        mode = PyUnicode_AsUTF8AndSize(fastargs[1], &mode_length);
+        mode = PyUnicode_AsUTF8(fastargs[1]);
         if (mode == NULL) {
             goto exit;
         }
-        if (strlen(mode) != (size_t)mode_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -457,4 +452,4 @@ _io__WindowsConsoleIO_isatty(winconsoleio *self, PyObject *Py_UNUSED(ignored))
 #ifndef _IO__WINDOWSCONSOLEIO_ISATTY_METHODDEF
     #define _IO__WINDOWSCONSOLEIO_ISATTY_METHODDEF
 #endif /* !defined(_IO__WINDOWSCONSOLEIO_ISATTY_METHODDEF) */
-/*[clinic end generated code: output=04108fc26b187386 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=76408dd67894bc9c input=a9049054013a1b77]*/
diff --git a/Modules/_multiprocessing/clinic/multiprocessing.c.h b/Modules/_multiprocessing/clinic/multiprocessing.c.h
index 6d4f5c2afcf..9133d5d8bb0 100644
--- a/Modules/_multiprocessing/clinic/multiprocessing.c.h
+++ b/Modules/_multiprocessing/clinic/multiprocessing.c.h
@@ -138,15 +138,10 @@ _multiprocessing_sem_unlink(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("sem_unlink", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(arg, &name_length);
+    name = PyUnicode_AsUTF8(arg);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _multiprocessing_sem_unlink_impl(module, name);
 
 exit:
@@ -164,4 +159,4 @@ exit:
 #ifndef _MULTIPROCESSING_SEND_METHODDEF
     #define _MULTIPROCESSING_SEND_METHODDEF
 #endif /* !defined(_MULTIPROCESSING_SEND_METHODDEF) */
-/*[clinic end generated code: output=73b4cb8428d816da input=a9049054013a1b77]*/
+/*[clinic end generated code: output=c6735cbc59b6f324 input=a9049054013a1b77]*/
diff --git a/Modules/_multiprocessing/clinic/semaphore.c.h b/Modules/_multiprocessing/clinic/semaphore.c.h
index 7c855113113..ae340c2f57a 100644
--- a/Modules/_multiprocessing/clinic/semaphore.c.h
+++ b/Modules/_multiprocessing/clinic/semaphore.c.h
@@ -266,15 +266,10 @@ _multiprocessing_SemLock(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         _PyArg_BadArgument("SemLock", "argument 'name'", "str", fastargs[3]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(fastargs[3], &name_length);
+    name = PyUnicode_AsUTF8(fastargs[3]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     unlink = PyObject_IsTrue(fastargs[4]);
     if (unlink < 0) {
         goto exit;
@@ -542,4 +537,4 @@ exit:
 #ifndef _MULTIPROCESSING_SEMLOCK___EXIT___METHODDEF
     #define _MULTIPROCESSING_SEMLOCK___EXIT___METHODDEF
 #endif /* !defined(_MULTIPROCESSING_SEMLOCK___EXIT___METHODDEF) */
-/*[clinic end generated code: output=d57992037e6770b6 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=fd94dc907e6ab57f input=a9049054013a1b77]*/
diff --git a/Modules/_sqlite/clinic/connection.c.h b/Modules/_sqlite/clinic/connection.c.h
index db5eb77891e..8e1a57415c2 100644
--- a/Modules/_sqlite/clinic/connection.c.h
+++ b/Modules/_sqlite/clinic/connection.c.h
@@ -297,28 +297,18 @@ blobopen(pysqlite_Connection *self, PyObject *const *args, Py_ssize_t nargs, PyO
         _PyArg_BadArgument("blobopen", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t table_length;
-    table = PyUnicode_AsUTF8AndSize(args[0], &table_length);
+    table = PyUnicode_AsUTF8(args[0]);
     if (table == NULL) {
         goto exit;
     }
-    if (strlen(table) != (size_t)table_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (!PyUnicode_Check(args[1])) {
         _PyArg_BadArgument("blobopen", "argument 2", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t col_length;
-    col = PyUnicode_AsUTF8AndSize(args[1], &col_length);
+    col = PyUnicode_AsUTF8(args[1]);
     if (col == NULL) {
         goto exit;
     }
-    if (strlen(col) != (size_t)col_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (!sqlite3_int64_converter(args[2], &row)) {
         goto exit;
     }
@@ -338,15 +328,10 @@ blobopen(pysqlite_Connection *self, PyObject *const *args, Py_ssize_t nargs, PyO
         _PyArg_BadArgument("blobopen", "argument 'name'", "str", args[4]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[4], &name_length);
+    name = PyUnicode_AsUTF8(args[4]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_kwonly:
     return_value = blobopen_impl(self, table, col, row, readonly, name);
 
@@ -499,15 +484,10 @@ pysqlite_connection_create_function(pysqlite_Connection *self, PyTypeObject *cls
         _PyArg_BadArgument("create_function", "argument 'name'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[0], &name_length);
+    name = PyUnicode_AsUTF8(args[0]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     narg = PyLong_AsInt(args[1]);
     if (narg == -1 && PyErr_Occurred()) {
         goto exit;
@@ -582,15 +562,10 @@ create_window_function(pysqlite_Connection *self, PyTypeObject *cls, PyObject *c
         _PyArg_BadArgument("create_window_function", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[0], &name_length);
+    name = PyUnicode_AsUTF8(args[0]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     num_params = PyLong_AsInt(args[1]);
     if (num_params == -1 && PyErr_Occurred()) {
         goto exit;
@@ -688,15 +663,10 @@ pysqlite_connection_create_aggregate(pysqlite_Connection *self, PyTypeObject *cl
         _PyArg_BadArgument("create_aggregate", "argument 'name'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[0], &name_length);
+    name = PyUnicode_AsUTF8(args[0]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     n_arg = PyLong_AsInt(args[1]);
     if (n_arg == -1 && PyErr_Occurred()) {
         goto exit;
@@ -1063,15 +1033,10 @@ pysqlite_connection_load_extension(pysqlite_Connection *self, PyObject *const *a
         _PyArg_BadArgument("load_extension", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t extension_name_length;
-    extension_name = PyUnicode_AsUTF8AndSize(args[0], &extension_name_length);
+    extension_name = PyUnicode_AsUTF8(args[0]);
     if (extension_name == NULL) {
         goto exit;
     }
-    if (strlen(extension_name) != (size_t)extension_name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (!noptargs) {
         goto skip_optional_kwonly;
     }
@@ -1079,15 +1044,10 @@ pysqlite_connection_load_extension(pysqlite_Connection *self, PyObject *const *a
         entrypoint = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t entrypoint_length;
-        entrypoint = PyUnicode_AsUTF8AndSize(args[1], &entrypoint_length);
+        entrypoint = PyUnicode_AsUTF8(args[1]);
         if (entrypoint == NULL) {
             goto exit;
         }
-        if (strlen(entrypoint) != (size_t)entrypoint_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("load_extension", "argument 'entrypoint'", "str or None", args[1]);
@@ -1306,15 +1266,10 @@ pysqlite_connection_backup(pysqlite_Connection *self, PyObject *const *args, Py_
             _PyArg_BadArgument("backup", "argument 'name'", "str", args[3]);
             goto exit;
         }
-        Py_ssize_t name_length;
-        name = PyUnicode_AsUTF8AndSize(args[3], &name_length);
+        name = PyUnicode_AsUTF8(args[3]);
         if (name == NULL) {
             goto exit;
         }
-        if (strlen(name) != (size_t)name_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_kwonly;
         }
@@ -1380,15 +1335,10 @@ pysqlite_connection_create_collation(pysqlite_Connection *self, PyTypeObject *cl
         _PyArg_BadArgument("create_collation", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[0], &name_length);
+    name = PyUnicode_AsUTF8(args[0]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     callable = args[1];
     return_value = pysqlite_connection_create_collation_impl(self, cls, name, callable);
 
@@ -1462,15 +1412,10 @@ serialize(pysqlite_Connection *self, PyObject *const *args, Py_ssize_t nargs, Py
         _PyArg_BadArgument("serialize", "argument 'name'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[0], &name_length);
+    name = PyUnicode_AsUTF8(args[0]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_kwonly:
     return_value = serialize_impl(self, name);
 
@@ -1565,15 +1510,10 @@ deserialize(pysqlite_Connection *self, PyObject *const *args, Py_ssize_t nargs,
         _PyArg_BadArgument("deserialize", "argument 'name'", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[1], &name_length);
+    name = PyUnicode_AsUTF8(args[1]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_kwonly:
     return_value = deserialize_impl(self, &data, name);
 
@@ -1818,4 +1758,4 @@ exit:
 #ifndef DESERIALIZE_METHODDEF
     #define DESERIALIZE_METHODDEF
 #endif /* !defined(DESERIALIZE_METHODDEF) */
-/*[clinic end generated code: output=90b5b9c14261b8d7 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=7d2a4d9272f7cb9e input=a9049054013a1b77]*/
diff --git a/Modules/_sqlite/clinic/cursor.c.h b/Modules/_sqlite/clinic/cursor.c.h
index a13e0d0745b..7a5850312ee 100644
--- a/Modules/_sqlite/clinic/cursor.c.h
+++ b/Modules/_sqlite/clinic/cursor.c.h
@@ -135,15 +135,10 @@ pysqlite_cursor_executescript(pysqlite_Cursor *self, PyObject *arg)
         _PyArg_BadArgument("executescript", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t sql_script_length;
-    sql_script = PyUnicode_AsUTF8AndSize(arg, &sql_script_length);
+    sql_script = PyUnicode_AsUTF8(arg);
     if (sql_script == NULL) {
         goto exit;
     }
-    if (strlen(sql_script) != (size_t)sql_script_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = pysqlite_cursor_executescript_impl(self, sql_script);
 
 exit:
@@ -313,4 +308,4 @@ pysqlite_cursor_close(pysqlite_Cursor *self, PyObject *Py_UNUSED(ignored))
 {
     return pysqlite_cursor_close_impl(self);
 }
-/*[clinic end generated code: output=a8ce095c3c80cf65 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=c772882c7df587ea input=a9049054013a1b77]*/
diff --git a/Modules/_sqlite/clinic/module.c.h b/Modules/_sqlite/clinic/module.c.h
index 529dc4e281e..d3c7ad8b7ca 100644
--- a/Modules/_sqlite/clinic/module.c.h
+++ b/Modules/_sqlite/clinic/module.c.h
@@ -60,15 +60,10 @@ pysqlite_complete_statement(PyObject *module, PyObject *const *args, Py_ssize_t
         _PyArg_BadArgument("complete_statement", "argument 'statement'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t statement_length;
-    statement = PyUnicode_AsUTF8AndSize(args[0], &statement_length);
+    statement = PyUnicode_AsUTF8(args[0]);
     if (statement == NULL) {
         goto exit;
     }
-    if (strlen(statement) != (size_t)statement_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = pysqlite_complete_statement_impl(module, statement);
 
 exit:
@@ -208,4 +203,4 @@ skip_optional:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=457ab0fdbb9e1880 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=19016e67830c19eb input=a9049054013a1b77]*/
diff --git a/Modules/_testcapi/clinic/exceptions.c.h b/Modules/_testcapi/clinic/exceptions.c.h
index a797444c1a7..80c52f48ced 100644
--- a/Modules/_testcapi/clinic/exceptions.c.h
+++ b/Modules/_testcapi/clinic/exceptions.c.h
@@ -112,15 +112,10 @@ _testcapi_make_exception_with_doc(PyObject *module, PyObject *const *args, Py_ss
         _PyArg_BadArgument("make_exception_with_doc", "argument 'name'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[0], &name_length);
+    name = PyUnicode_AsUTF8(args[0]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (!noptargs) {
         goto skip_optional_pos;
     }
@@ -129,15 +124,10 @@ _testcapi_make_exception_with_doc(PyObject *module, PyObject *const *args, Py_ss
             _PyArg_BadArgument("make_exception_with_doc", "argument 'doc'", "str", args[1]);
             goto exit;
         }
-        Py_ssize_t doc_length;
-        doc = PyUnicode_AsUTF8AndSize(args[1], &doc_length);
+        doc = PyUnicode_AsUTF8(args[1]);
         if (doc == NULL) {
             goto exit;
         }
-        if (strlen(doc) != (size_t)doc_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -456,4 +446,4 @@ _testcapi_unstable_exc_prep_reraise_star(PyObject *module, PyObject *const *args
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=0b11ef105030a48e input=a9049054013a1b77]*/
+/*[clinic end generated code: output=6f2b4f773e0ae755 input=a9049054013a1b77]*/
diff --git a/Modules/cjkcodecs/clinic/multibytecodec.c.h b/Modules/cjkcodecs/clinic/multibytecodec.c.h
index 305ade17b1f..fec223930cd 100644
--- a/Modules/cjkcodecs/clinic/multibytecodec.c.h
+++ b/Modules/cjkcodecs/clinic/multibytecodec.c.h
@@ -73,15 +73,10 @@ _multibytecodec_MultibyteCodec_encode(MultibyteCodecObject *self, PyObject *cons
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("encode", "argument 'errors'", "str or None", args[1]);
@@ -161,15 +156,10 @@ _multibytecodec_MultibyteCodec_decode(MultibyteCodecObject *self, PyObject *cons
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("decode", "argument 'errors'", "str or None", args[1]);
@@ -682,4 +672,4 @@ PyDoc_STRVAR(_multibytecodec___create_codec__doc__,
 
 #define _MULTIBYTECODEC___CREATE_CODEC_METHODDEF    \
     {"__create_codec", (PyCFunction)_multibytecodec___create_codec, METH_O, _multibytecodec___create_codec__doc__},
-/*[clinic end generated code: output=219a363662d2fbff input=a9049054013a1b77]*/
+/*[clinic end generated code: output=b35a5c3797e0e54a input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_codecsmodule.c.h b/Modules/clinic/_codecsmodule.c.h
index 12fea806ab5..bf17596274b 100644
--- a/Modules/clinic/_codecsmodule.c.h
+++ b/Modules/clinic/_codecsmodule.c.h
@@ -54,15 +54,10 @@ _codecs_lookup(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("lookup", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t encoding_length;
-    encoding = PyUnicode_AsUTF8AndSize(arg, &encoding_length);
+    encoding = PyUnicode_AsUTF8(arg);
     if (encoding == NULL) {
         goto exit;
     }
-    if (strlen(encoding) != (size_t)encoding_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _codecs_lookup_impl(module, encoding);
 
 exit:
@@ -136,15 +131,10 @@ _codecs_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
             _PyArg_BadArgument("encode", "argument 'encoding'", "str", args[1]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(args[1], &encoding_length);
+        encoding = PyUnicode_AsUTF8(args[1]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -153,15 +143,10 @@ _codecs_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
         _PyArg_BadArgument("encode", "argument 'errors'", "str", args[2]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(args[2], &errors_length);
+    errors = PyUnicode_AsUTF8(args[2]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = _codecs_encode_impl(module, obj, encoding, errors);
 
@@ -236,15 +221,10 @@ _codecs_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
             _PyArg_BadArgument("decode", "argument 'encoding'", "str", args[1]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(args[1], &encoding_length);
+        encoding = PyUnicode_AsUTF8(args[1]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -253,15 +233,10 @@ _codecs_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
         _PyArg_BadArgument("decode", "argument 'errors'", "str", args[2]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(args[2], &errors_length);
+    errors = PyUnicode_AsUTF8(args[2]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = _codecs_decode_impl(module, obj, encoding, errors);
 
@@ -311,15 +286,10 @@ _codecs_escape_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("escape_decode", "argument 2", "str or None", args[1]);
@@ -371,15 +341,10 @@ _codecs_escape_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("escape_encode", "argument 2", "str or None", args[1]);
@@ -425,15 +390,10 @@ _codecs_utf_7_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_7_decode", "argument 2", "str or None", args[1]);
@@ -491,15 +451,10 @@ _codecs_utf_8_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_8_decode", "argument 2", "str or None", args[1]);
@@ -557,15 +512,10 @@ _codecs_utf_16_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_16_decode", "argument 2", "str or None", args[1]);
@@ -623,15 +573,10 @@ _codecs_utf_16_le_decode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_16_le_decode", "argument 2", "str or None", args[1]);
@@ -689,15 +634,10 @@ _codecs_utf_16_be_decode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_16_be_decode", "argument 2", "str or None", args[1]);
@@ -757,15 +697,10 @@ _codecs_utf_16_ex_decode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_16_ex_decode", "argument 2", "str or None", args[1]);
@@ -830,15 +765,10 @@ _codecs_utf_32_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_32_decode", "argument 2", "str or None", args[1]);
@@ -896,15 +826,10 @@ _codecs_utf_32_le_decode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_32_le_decode", "argument 2", "str or None", args[1]);
@@ -962,15 +887,10 @@ _codecs_utf_32_be_decode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_32_be_decode", "argument 2", "str or None", args[1]);
@@ -1030,15 +950,10 @@ _codecs_utf_32_ex_decode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_32_ex_decode", "argument 2", "str or None", args[1]);
@@ -1113,15 +1028,10 @@ _codecs_unicode_escape_decode(PyObject *module, PyObject *const *args, Py_ssize_
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("unicode_escape_decode", "argument 2", "str or None", args[1]);
@@ -1189,15 +1099,10 @@ _codecs_raw_unicode_escape_decode(PyObject *module, PyObject *const *args, Py_ss
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("raw_unicode_escape_decode", "argument 2", "str or None", args[1]);
@@ -1254,15 +1159,10 @@ _codecs_latin_1_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("latin_1_decode", "argument 2", "str or None", args[1]);
@@ -1312,15 +1212,10 @@ _codecs_ascii_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("ascii_decode", "argument 2", "str or None", args[1]);
@@ -1371,15 +1266,10 @@ _codecs_charmap_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("charmap_decode", "argument 2", "str or None", args[1]);
@@ -1436,15 +1326,10 @@ _codecs_mbcs_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("mbcs_decode", "argument 2", "str or None", args[1]);
@@ -1506,15 +1391,10 @@ _codecs_oem_decode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("oem_decode", "argument 2", "str or None", args[1]);
@@ -1581,15 +1461,10 @@ _codecs_code_page_decode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[2])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[2], &errors_length);
+        errors = PyUnicode_AsUTF8(args[2]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("code_page_decode", "argument 3", "str or None", args[2]);
@@ -1658,15 +1533,10 @@ _codecs_readbuffer_encode(PyObject *module, PyObject *const *args, Py_ssize_t na
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("readbuffer_encode", "argument 2", "str or None", args[1]);
@@ -1718,15 +1588,10 @@ _codecs_utf_7_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_7_encode", "argument 2", "str or None", args[1]);
@@ -1773,15 +1638,10 @@ _codecs_utf_8_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_8_encode", "argument 2", "str or None", args[1]);
@@ -1829,15 +1689,10 @@ _codecs_utf_16_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_16_encode", "argument 2", "str or None", args[1]);
@@ -1891,15 +1746,10 @@ _codecs_utf_16_le_encode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_16_le_encode", "argument 2", "str or None", args[1]);
@@ -1946,15 +1796,10 @@ _codecs_utf_16_be_encode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_16_be_encode", "argument 2", "str or None", args[1]);
@@ -2002,15 +1847,10 @@ _codecs_utf_32_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_32_encode", "argument 2", "str or None", args[1]);
@@ -2064,15 +1904,10 @@ _codecs_utf_32_le_encode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_32_le_encode", "argument 2", "str or None", args[1]);
@@ -2119,15 +1954,10 @@ _codecs_utf_32_be_encode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("utf_32_be_encode", "argument 2", "str or None", args[1]);
@@ -2174,15 +2004,10 @@ _codecs_unicode_escape_encode(PyObject *module, PyObject *const *args, Py_ssize_
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("unicode_escape_encode", "argument 2", "str or None", args[1]);
@@ -2229,15 +2054,10 @@ _codecs_raw_unicode_escape_encode(PyObject *module, PyObject *const *args, Py_ss
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("raw_unicode_escape_encode", "argument 2", "str or None", args[1]);
@@ -2284,15 +2104,10 @@ _codecs_latin_1_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("latin_1_encode", "argument 2", "str or None", args[1]);
@@ -2339,15 +2154,10 @@ _codecs_ascii_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("ascii_encode", "argument 2", "str or None", args[1]);
@@ -2395,15 +2205,10 @@ _codecs_charmap_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("charmap_encode", "argument 2", "str or None", args[1]);
@@ -2483,15 +2288,10 @@ _codecs_mbcs_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("mbcs_encode", "argument 2", "str or None", args[1]);
@@ -2541,15 +2341,10 @@ _codecs_oem_encode(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         errors = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+        errors = PyUnicode_AsUTF8(args[1]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("oem_encode", "argument 2", "str or None", args[1]);
@@ -2605,15 +2400,10 @@ _codecs_code_page_encode(PyObject *module, PyObject *const *args, Py_ssize_t nar
         errors = NULL;
     }
     else if (PyUnicode_Check(args[2])) {
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[2], &errors_length);
+        errors = PyUnicode_AsUTF8(args[2]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("code_page_encode", "argument 3", "str or None", args[2]);
@@ -2659,15 +2449,10 @@ _codecs_register_error(PyObject *module, PyObject *const *args, Py_ssize_t nargs
         _PyArg_BadArgument("register_error", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(args[0], &errors_length);
+    errors = PyUnicode_AsUTF8(args[0]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     handler = args[1];
     return_value = _codecs_register_error_impl(module, errors, handler);
 
@@ -2700,15 +2485,10 @@ _codecs_lookup_error(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("lookup_error", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(arg, &name_length);
+    name = PyUnicode_AsUTF8(arg);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _codecs_lookup_error_impl(module, name);
 
 exit:
@@ -2738,4 +2518,4 @@ exit:
 #ifndef _CODECS_CODE_PAGE_ENCODE_METHODDEF
     #define _CODECS_CODE_PAGE_ENCODE_METHODDEF
 #endif /* !defined(_CODECS_CODE_PAGE_ENCODE_METHODDEF) */
-/*[clinic end generated code: output=d8d9e372f7ccba35 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=5c95a170d813a46f input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_cursesmodule.c.h b/Modules/clinic/_cursesmodule.c.h
index f7e0aaf7b23..409c6157857 100644
--- a/Modules/clinic/_cursesmodule.c.h
+++ b/Modules/clinic/_cursesmodule.c.h
@@ -2726,15 +2726,10 @@ _curses_setupterm(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyO
             term = NULL;
         }
         else if (PyUnicode_Check(args[0])) {
-            Py_ssize_t term_length;
-            term = PyUnicode_AsUTF8AndSize(args[0], &term_length);
+            term = PyUnicode_AsUTF8(args[0]);
             if (term == NULL) {
                 goto exit;
             }
-            if (strlen(term) != (size_t)term_length) {
-                PyErr_SetString(PyExc_ValueError, "embedded null character");
-                goto exit;
-            }
         }
         else {
             _PyArg_BadArgument("setupterm", "argument 'term'", "str or None", args[0]);
@@ -3926,15 +3921,10 @@ _curses_tigetflag(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("tigetflag", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t capname_length;
-    capname = PyUnicode_AsUTF8AndSize(arg, &capname_length);
+    capname = PyUnicode_AsUTF8(arg);
     if (capname == NULL) {
         goto exit;
     }
-    if (strlen(capname) != (size_t)capname_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _curses_tigetflag_impl(module, capname);
 
 exit:
@@ -3969,15 +3959,10 @@ _curses_tigetnum(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("tigetnum", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t capname_length;
-    capname = PyUnicode_AsUTF8AndSize(arg, &capname_length);
+    capname = PyUnicode_AsUTF8(arg);
     if (capname == NULL) {
         goto exit;
     }
-    if (strlen(capname) != (size_t)capname_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _curses_tigetnum_impl(module, capname);
 
 exit:
@@ -4012,15 +3997,10 @@ _curses_tigetstr(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("tigetstr", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t capname_length;
-    capname = PyUnicode_AsUTF8AndSize(arg, &capname_length);
+    capname = PyUnicode_AsUTF8(arg);
     if (capname == NULL) {
         goto exit;
     }
-    if (strlen(capname) != (size_t)capname_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _curses_tigetstr_impl(module, capname);
 
 exit:
@@ -4318,4 +4298,4 @@ _curses_has_extended_color_support(PyObject *module, PyObject *Py_UNUSED(ignored
 #ifndef _CURSES_USE_DEFAULT_COLORS_METHODDEF
     #define _CURSES_USE_DEFAULT_COLORS_METHODDEF
 #endif /* !defined(_CURSES_USE_DEFAULT_COLORS_METHODDEF) */
-/*[clinic end generated code: output=96887782374f070a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=555e266fc4838612 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_dbmmodule.c.h b/Modules/clinic/_dbmmodule.c.h
index 5a4aba2825e..4b4baf8cd49 100644
--- a/Modules/clinic/_dbmmodule.c.h
+++ b/Modules/clinic/_dbmmodule.c.h
@@ -196,15 +196,10 @@ dbmopen(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("open", "argument 2", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t flags_length;
-    flags = PyUnicode_AsUTF8AndSize(args[1], &flags_length);
+    flags = PyUnicode_AsUTF8(args[1]);
     if (flags == NULL) {
         goto exit;
     }
-    if (strlen(flags) != (size_t)flags_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (nargs < 3) {
         goto skip_optional;
     }
@@ -218,4 +213,4 @@ skip_optional:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=96fdd4bd7bd256c5 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=48183905532205c2 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_elementtree.c.h b/Modules/clinic/_elementtree.c.h
index 02375c8a61e..a14b3815e56 100644
--- a/Modules/clinic/_elementtree.c.h
+++ b/Modules/clinic/_elementtree.c.h
@@ -1131,15 +1131,10 @@ _elementtree_XMLParser___init__(PyObject *self, PyObject *args, PyObject *kwargs
         encoding = NULL;
     }
     else if (PyUnicode_Check(fastargs[1])) {
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(fastargs[1], &encoding_length);
+        encoding = PyUnicode_AsUTF8(fastargs[1]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("XMLParser", "argument 'encoding'", "str or None", fastargs[1]);
@@ -1219,4 +1214,4 @@ skip_optional:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=8fdaa17d3262800a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=399d9d5c9435070b input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_gdbmmodule.c.h b/Modules/clinic/_gdbmmodule.c.h
index c7164e519d0..ab7288ee223 100644
--- a/Modules/clinic/_gdbmmodule.c.h
+++ b/Modules/clinic/_gdbmmodule.c.h
@@ -318,15 +318,10 @@ dbmopen(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("open", "argument 2", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t flags_length;
-    flags = PyUnicode_AsUTF8AndSize(args[1], &flags_length);
+    flags = PyUnicode_AsUTF8(args[1]);
     if (flags == NULL) {
         goto exit;
     }
-    if (strlen(flags) != (size_t)flags_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (nargs < 3) {
         goto skip_optional;
     }
@@ -340,4 +335,4 @@ skip_optional:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=c5ee922363d5a81f input=a9049054013a1b77]*/
+/*[clinic end generated code: output=725cafd8b2d8cfdb input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_hashopenssl.c.h b/Modules/clinic/_hashopenssl.c.h
index 58650dff288..e360e985007 100644
--- a/Modules/clinic/_hashopenssl.c.h
+++ b/Modules/clinic/_hashopenssl.c.h
@@ -1278,15 +1278,10 @@ pbkdf2_hmac(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject
         _PyArg_BadArgument("pbkdf2_hmac", "argument 'hash_name'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t hash_name_length;
-    hash_name = PyUnicode_AsUTF8AndSize(args[0], &hash_name_length);
+    hash_name = PyUnicode_AsUTF8(args[0]);
     if (hash_name == NULL) {
         goto exit;
     }
-    if (strlen(hash_name) != (size_t)hash_name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (PyObject_GetBuffer(args[1], &password, PyBUF_SIMPLE) != 0) {
         goto exit;
     }
@@ -1824,4 +1819,4 @@ exit:
 #ifndef _HASHLIB_SCRYPT_METHODDEF
     #define _HASHLIB_SCRYPT_METHODDEF
 #endif /* !defined(_HASHLIB_SCRYPT_METHODDEF) */
-/*[clinic end generated code: output=b7eddeb3d6ccdeec input=a9049054013a1b77]*/
+/*[clinic end generated code: output=bc372898eaa3e000 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_localemodule.c.h b/Modules/clinic/_localemodule.c.h
index 5e0880b0d0b..2663b28fa72 100644
--- a/Modules/clinic/_localemodule.c.h
+++ b/Modules/clinic/_localemodule.c.h
@@ -37,15 +37,10 @@ _locale_setlocale(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         locale = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t locale_length;
-        locale = PyUnicode_AsUTF8AndSize(args[1], &locale_length);
+        locale = PyUnicode_AsUTF8(args[1]);
         if (locale == NULL) {
             goto exit;
         }
-        if (strlen(locale) != (size_t)locale_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("setlocale", "argument 2", "str or None", args[1]);
@@ -230,15 +225,10 @@ _locale_gettext(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("gettext", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t in_length;
-    in = PyUnicode_AsUTF8AndSize(arg, &in_length);
+    in = PyUnicode_AsUTF8(arg);
     if (in == NULL) {
         goto exit;
     }
-    if (strlen(in) != (size_t)in_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _locale_gettext_impl(module, in);
 
 exit:
@@ -277,15 +267,10 @@ _locale_dgettext(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         domain = NULL;
     }
     else if (PyUnicode_Check(args[0])) {
-        Py_ssize_t domain_length;
-        domain = PyUnicode_AsUTF8AndSize(args[0], &domain_length);
+        domain = PyUnicode_AsUTF8(args[0]);
         if (domain == NULL) {
             goto exit;
         }
-        if (strlen(domain) != (size_t)domain_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("dgettext", "argument 1", "str or None", args[0]);
@@ -295,15 +280,10 @@ _locale_dgettext(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("dgettext", "argument 2", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t in_length;
-    in = PyUnicode_AsUTF8AndSize(args[1], &in_length);
+    in = PyUnicode_AsUTF8(args[1]);
     if (in == NULL) {
         goto exit;
     }
-    if (strlen(in) != (size_t)in_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _locale_dgettext_impl(module, domain, in);
 
 exit:
@@ -342,15 +322,10 @@ _locale_dcgettext(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         domain = NULL;
     }
     else if (PyUnicode_Check(args[0])) {
-        Py_ssize_t domain_length;
-        domain = PyUnicode_AsUTF8AndSize(args[0], &domain_length);
+        domain = PyUnicode_AsUTF8(args[0]);
         if (domain == NULL) {
             goto exit;
         }
-        if (strlen(domain) != (size_t)domain_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("dcgettext", "argument 1", "str or None", args[0]);
@@ -360,15 +335,10 @@ _locale_dcgettext(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("dcgettext", "argument 2", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t msgid_length;
-    msgid = PyUnicode_AsUTF8AndSize(args[1], &msgid_length);
+    msgid = PyUnicode_AsUTF8(args[1]);
     if (msgid == NULL) {
         goto exit;
     }
-    if (strlen(msgid) != (size_t)msgid_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     category = PyLong_AsInt(args[2]);
     if (category == -1 && PyErr_Occurred()) {
         goto exit;
@@ -405,15 +375,10 @@ _locale_textdomain(PyObject *module, PyObject *arg)
         domain = NULL;
     }
     else if (PyUnicode_Check(arg)) {
-        Py_ssize_t domain_length;
-        domain = PyUnicode_AsUTF8AndSize(arg, &domain_length);
+        domain = PyUnicode_AsUTF8(arg);
         if (domain == NULL) {
             goto exit;
         }
-        if (strlen(domain) != (size_t)domain_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("textdomain", "argument", "str or None", arg);
@@ -456,15 +421,10 @@ _locale_bindtextdomain(PyObject *module, PyObject *const *args, Py_ssize_t nargs
         _PyArg_BadArgument("bindtextdomain", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t domain_length;
-    domain = PyUnicode_AsUTF8AndSize(args[0], &domain_length);
+    domain = PyUnicode_AsUTF8(args[0]);
     if (domain == NULL) {
         goto exit;
     }
-    if (strlen(domain) != (size_t)domain_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     dirname_obj = args[1];
     return_value = _locale_bindtextdomain_impl(module, domain, dirname_obj);
 
@@ -503,28 +463,18 @@ _locale_bind_textdomain_codeset(PyObject *module, PyObject *const *args, Py_ssiz
         _PyArg_BadArgument("bind_textdomain_codeset", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t domain_length;
-    domain = PyUnicode_AsUTF8AndSize(args[0], &domain_length);
+    domain = PyUnicode_AsUTF8(args[0]);
     if (domain == NULL) {
         goto exit;
     }
-    if (strlen(domain) != (size_t)domain_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (args[1] == Py_None) {
         codeset = NULL;
     }
     else if (PyUnicode_Check(args[1])) {
-        Py_ssize_t codeset_length;
-        codeset = PyUnicode_AsUTF8AndSize(args[1], &codeset_length);
+        codeset = PyUnicode_AsUTF8(args[1]);
         if (codeset == NULL) {
             goto exit;
         }
-        if (strlen(codeset) != (size_t)codeset_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("bind_textdomain_codeset", "argument 2", "str or None", args[1]);
@@ -595,4 +545,4 @@ _locale_getencoding(PyObject *module, PyObject *Py_UNUSED(ignored))
 #ifndef _LOCALE_BIND_TEXTDOMAIN_CODESET_METHODDEF
     #define _LOCALE_BIND_TEXTDOMAIN_CODESET_METHODDEF
 #endif /* !defined(_LOCALE_BIND_TEXTDOMAIN_CODESET_METHODDEF) */
-/*[clinic end generated code: output=034a3c219466d207 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=14a4bffed066ebb3 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_pickle.c.h b/Modules/clinic/_pickle.c.h
index 932ace190e6..75edfd03e8c 100644
--- a/Modules/clinic/_pickle.c.h
+++ b/Modules/clinic/_pickle.c.h
@@ -466,15 +466,10 @@ _pickle_Unpickler___init__(PyObject *self, PyObject *args, PyObject *kwargs)
             _PyArg_BadArgument("Unpickler", "argument 'encoding'", "str", fastargs[2]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(fastargs[2], &encoding_length);
+        encoding = PyUnicode_AsUTF8(fastargs[2]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_kwonly;
         }
@@ -484,15 +479,10 @@ _pickle_Unpickler___init__(PyObject *self, PyObject *args, PyObject *kwargs)
             _PyArg_BadArgument("Unpickler", "argument 'errors'", "str", fastargs[3]);
             goto exit;
         }
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(fastargs[3], &errors_length);
+        errors = PyUnicode_AsUTF8(fastargs[3]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_kwonly;
         }
@@ -870,15 +860,10 @@ _pickle_load(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject
             _PyArg_BadArgument("load", "argument 'encoding'", "str", args[2]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(args[2], &encoding_length);
+        encoding = PyUnicode_AsUTF8(args[2]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_kwonly;
         }
@@ -888,15 +873,10 @@ _pickle_load(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject
             _PyArg_BadArgument("load", "argument 'errors'", "str", args[3]);
             goto exit;
         }
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[3], &errors_length);
+        errors = PyUnicode_AsUTF8(args[3]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_kwonly;
         }
@@ -996,15 +976,10 @@ _pickle_loads(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObjec
             _PyArg_BadArgument("loads", "argument 'encoding'", "str", args[2]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(args[2], &encoding_length);
+        encoding = PyUnicode_AsUTF8(args[2]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_kwonly;
         }
@@ -1014,15 +989,10 @@ _pickle_loads(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObjec
             _PyArg_BadArgument("loads", "argument 'errors'", "str", args[3]);
             goto exit;
         }
-        Py_ssize_t errors_length;
-        errors = PyUnicode_AsUTF8AndSize(args[3], &errors_length);
+        errors = PyUnicode_AsUTF8(args[3]);
         if (errors == NULL) {
             goto exit;
         }
-        if (strlen(errors) != (size_t)errors_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_kwonly;
         }
@@ -1034,4 +1004,4 @@ skip_optional_kwonly:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=7f0564b5fb5410a8 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=1c675a6680a6b90c input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_ssl.c.h b/Modules/clinic/_ssl.c.h
index 88401b0490a..7aa435f0b8f 100644
--- a/Modules/clinic/_ssl.c.h
+++ b/Modules/clinic/_ssl.c.h
@@ -391,15 +391,10 @@ _ssl__SSLSocket_get_channel_binding(PySSLSocket *self, PyObject *const *args, Py
         _PyArg_BadArgument("get_channel_binding", "argument 'cb_type'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t cb_type_length;
-    cb_type = PyUnicode_AsUTF8AndSize(args[0], &cb_type_length);
+    cb_type = PyUnicode_AsUTF8(args[0]);
     if (cb_type == NULL) {
         goto exit;
     }
-    if (strlen(cb_type) != (size_t)cb_type_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = _ssl__SSLSocket_get_channel_binding_impl(self, cb_type);
 
@@ -473,15 +468,10 @@ _ssl__SSLContext_set_ciphers(PySSLContext *self, PyObject *arg)
         _PyArg_BadArgument("set_ciphers", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t cipherlist_length;
-    cipherlist = PyUnicode_AsUTF8AndSize(arg, &cipherlist_length);
+    cipherlist = PyUnicode_AsUTF8(arg);
     if (cipherlist == NULL) {
         goto exit;
     }
-    if (strlen(cipherlist) != (size_t)cipherlist_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _ssl__SSLContext_set_ciphers_impl(self, cipherlist);
 
 exit:
@@ -1316,15 +1306,10 @@ _ssl_txt2obj(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject
         _PyArg_BadArgument("txt2obj", "argument 'txt'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t txt_length;
-    txt = PyUnicode_AsUTF8AndSize(args[0], &txt_length);
+    txt = PyUnicode_AsUTF8(args[0]);
     if (txt == NULL) {
         goto exit;
     }
-    if (strlen(txt) != (size_t)txt_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (!noptargs) {
         goto skip_optional_pos;
     }
@@ -1427,15 +1412,10 @@ _ssl_enum_certificates(PyObject *module, PyObject *const *args, Py_ssize_t nargs
         _PyArg_BadArgument("enum_certificates", "argument 'store_name'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t store_name_length;
-    store_name = PyUnicode_AsUTF8AndSize(args[0], &store_name_length);
+    store_name = PyUnicode_AsUTF8(args[0]);
     if (store_name == NULL) {
         goto exit;
     }
-    if (strlen(store_name) != (size_t)store_name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _ssl_enum_certificates_impl(module, store_name);
 
 exit:
@@ -1503,15 +1483,10 @@ _ssl_enum_crls(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
         _PyArg_BadArgument("enum_crls", "argument 'store_name'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t store_name_length;
-    store_name = PyUnicode_AsUTF8AndSize(args[0], &store_name_length);
+    store_name = PyUnicode_AsUTF8(args[0]);
     if (store_name == NULL) {
         goto exit;
     }
-    if (strlen(store_name) != (size_t)store_name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _ssl_enum_crls_impl(module, store_name);
 
 exit:
@@ -1527,4 +1502,4 @@ exit:
 #ifndef _SSL_ENUM_CRLS_METHODDEF
     #define _SSL_ENUM_CRLS_METHODDEF
 #endif /* !defined(_SSL_ENUM_CRLS_METHODDEF) */
-/*[clinic end generated code: output=aa6b0a898b6077fe input=a9049054013a1b77]*/
+/*[clinic end generated code: output=8350af68e0a56792 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_testclinic.c.h b/Modules/clinic/_testclinic.c.h
index fea30e77838..df81710364d 100644
--- a/Modules/clinic/_testclinic.c.h
+++ b/Modules/clinic/_testclinic.c.h
@@ -2935,15 +2935,10 @@ clone_f1(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kw
         _PyArg_BadArgument("clone_f1", "argument 'path'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t path_length;
-    path = PyUnicode_AsUTF8AndSize(args[0], &path_length);
+    path = PyUnicode_AsUTF8(args[0]);
     if (path == NULL) {
         goto exit;
     }
-    if (strlen(path) != (size_t)path_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = clone_f1_impl(module, path);
 
 exit:
@@ -3001,15 +2996,10 @@ clone_f2(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kw
         _PyArg_BadArgument("clone_f2", "argument 'path'", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t path_length;
-    path = PyUnicode_AsUTF8AndSize(args[0], &path_length);
+    path = PyUnicode_AsUTF8(args[0]);
     if (path == NULL) {
         goto exit;
     }
-    if (strlen(path) != (size_t)path_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = clone_f2_impl(module, path);
 
 exit:
@@ -3141,4 +3131,4 @@ skip_optional_pos:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=90743ac900d60f9f input=a9049054013a1b77]*/
+/*[clinic end generated code: output=32dc6ac90757da7a input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_tkinter.c.h b/Modules/clinic/_tkinter.c.h
index 188bcc773cf..1ff3cec568e 100644
--- a/Modules/clinic/_tkinter.c.h
+++ b/Modules/clinic/_tkinter.c.h
@@ -25,15 +25,10 @@ _tkinter_tkapp_eval(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("eval", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t script_length;
-    script = PyUnicode_AsUTF8AndSize(arg, &script_length);
+    script = PyUnicode_AsUTF8(arg);
     if (script == NULL) {
         goto exit;
     }
-    if (strlen(script) != (size_t)script_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_eval_impl(self, script);
 
 exit:
@@ -61,15 +56,10 @@ _tkinter_tkapp_evalfile(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("evalfile", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t fileName_length;
-    fileName = PyUnicode_AsUTF8AndSize(arg, &fileName_length);
+    fileName = PyUnicode_AsUTF8(arg);
     if (fileName == NULL) {
         goto exit;
     }
-    if (strlen(fileName) != (size_t)fileName_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_evalfile_impl(self, fileName);
 
 exit:
@@ -97,15 +87,10 @@ _tkinter_tkapp_record(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("record", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t script_length;
-    script = PyUnicode_AsUTF8AndSize(arg, &script_length);
+    script = PyUnicode_AsUTF8(arg);
     if (script == NULL) {
         goto exit;
     }
-    if (strlen(script) != (size_t)script_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_record_impl(self, script);
 
 exit:
@@ -133,15 +118,10 @@ _tkinter_tkapp_adderrorinfo(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("adderrorinfo", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t msg_length;
-    msg = PyUnicode_AsUTF8AndSize(arg, &msg_length);
+    msg = PyUnicode_AsUTF8(arg);
     if (msg == NULL) {
         goto exit;
     }
-    if (strlen(msg) != (size_t)msg_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_adderrorinfo_impl(self, msg);
 
 exit:
@@ -193,15 +173,10 @@ _tkinter_tkapp_exprstring(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("exprstring", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t s_length;
-    s = PyUnicode_AsUTF8AndSize(arg, &s_length);
+    s = PyUnicode_AsUTF8(arg);
     if (s == NULL) {
         goto exit;
     }
-    if (strlen(s) != (size_t)s_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_exprstring_impl(self, s);
 
 exit:
@@ -229,15 +204,10 @@ _tkinter_tkapp_exprlong(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("exprlong", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t s_length;
-    s = PyUnicode_AsUTF8AndSize(arg, &s_length);
+    s = PyUnicode_AsUTF8(arg);
     if (s == NULL) {
         goto exit;
     }
-    if (strlen(s) != (size_t)s_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_exprlong_impl(self, s);
 
 exit:
@@ -265,15 +235,10 @@ _tkinter_tkapp_exprdouble(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("exprdouble", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t s_length;
-    s = PyUnicode_AsUTF8AndSize(arg, &s_length);
+    s = PyUnicode_AsUTF8(arg);
     if (s == NULL) {
         goto exit;
     }
-    if (strlen(s) != (size_t)s_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_exprdouble_impl(self, s);
 
 exit:
@@ -301,15 +266,10 @@ _tkinter_tkapp_exprboolean(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("exprboolean", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t s_length;
-    s = PyUnicode_AsUTF8AndSize(arg, &s_length);
+    s = PyUnicode_AsUTF8(arg);
     if (s == NULL) {
         goto exit;
     }
-    if (strlen(s) != (size_t)s_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_exprboolean_impl(self, s);
 
 exit:
@@ -350,15 +310,10 @@ _tkinter_tkapp_createcommand(TkappObject *self, PyObject *const *args, Py_ssize_
         _PyArg_BadArgument("createcommand", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(args[0], &name_length);
+    name = PyUnicode_AsUTF8(args[0]);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     func = args[1];
     return_value = _tkinter_tkapp_createcommand_impl(self, name, func);
 
@@ -387,15 +342,10 @@ _tkinter_tkapp_deletecommand(TkappObject *self, PyObject *arg)
         _PyArg_BadArgument("deletecommand", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t name_length;
-    name = PyUnicode_AsUTF8AndSize(arg, &name_length);
+    name = PyUnicode_AsUTF8(arg);
     if (name == NULL) {
         goto exit;
     }
-    if (strlen(name) != (size_t)name_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _tkinter_tkapp_deletecommand_impl(self, name);
 
 exit:
@@ -694,15 +644,10 @@ _tkinter_create(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         screenName = NULL;
     }
     else if (PyUnicode_Check(args[0])) {
-        Py_ssize_t screenName_length;
-        screenName = PyUnicode_AsUTF8AndSize(args[0], &screenName_length);
+        screenName = PyUnicode_AsUTF8(args[0]);
         if (screenName == NULL) {
             goto exit;
         }
-        if (strlen(screenName) != (size_t)screenName_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("create", "argument 1", "str or None", args[0]);
@@ -715,15 +660,10 @@ _tkinter_create(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("create", "argument 2", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t baseName_length;
-    baseName = PyUnicode_AsUTF8AndSize(args[1], &baseName_length);
+    baseName = PyUnicode_AsUTF8(args[1]);
     if (baseName == NULL) {
         goto exit;
     }
-    if (strlen(baseName) != (size_t)baseName_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (nargs < 3) {
         goto skip_optional;
     }
@@ -731,15 +671,10 @@ _tkinter_create(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("create", "argument 3", "str", args[2]);
         goto exit;
     }
-    Py_ssize_t className_length;
-    className = PyUnicode_AsUTF8AndSize(args[2], &className_length);
+    className = PyUnicode_AsUTF8(args[2]);
     if (className == NULL) {
         goto exit;
     }
-    if (strlen(className) != (size_t)className_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (nargs < 4) {
         goto skip_optional;
     }
@@ -775,15 +710,10 @@ _tkinter_create(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         use = NULL;
     }
     else if (PyUnicode_Check(args[7])) {
-        Py_ssize_t use_length;
-        use = PyUnicode_AsUTF8AndSize(args[7], &use_length);
+        use = PyUnicode_AsUTF8(args[7]);
         if (use == NULL) {
             goto exit;
         }
-        if (strlen(use) != (size_t)use_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("create", "argument 8", "str or None", args[7]);
@@ -861,4 +791,4 @@ exit:
 #ifndef _TKINTER_TKAPP_DELETEFILEHANDLER_METHODDEF
     #define _TKINTER_TKAPP_DELETEFILEHANDLER_METHODDEF
 #endif /* !defined(_TKINTER_TKAPP_DELETEFILEHANDLER_METHODDEF) */
-/*[clinic end generated code: output=d447501ec5aa9447 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=0c8b5f960d7738fd input=a9049054013a1b77]*/
diff --git a/Modules/clinic/posixmodule.c.h b/Modules/clinic/posixmodule.c.h
index 9473dd70ff1..d91793c8be8 100644
--- a/Modules/clinic/posixmodule.c.h
+++ b/Modules/clinic/posixmodule.c.h
@@ -4672,15 +4672,10 @@ os_getgrouplist(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("getgrouplist", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t user_length;
-    user = PyUnicode_AsUTF8AndSize(args[0], &user_length);
+    user = PyUnicode_AsUTF8(args[0]);
     if (user == NULL) {
         goto exit;
     }
-    if (strlen(user) != (size_t)user_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     basegid = PyLong_AsInt(args[1]);
     if (basegid == -1 && PyErr_Occurred()) {
         goto exit;
@@ -4726,15 +4721,10 @@ os_getgrouplist(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("getgrouplist", "argument 1", "str", args[0]);
         goto exit;
     }
-    Py_ssize_t user_length;
-    user = PyUnicode_AsUTF8AndSize(args[0], &user_length);
+    user = PyUnicode_AsUTF8(args[0]);
     if (user == NULL) {
         goto exit;
     }
-    if (strlen(user) != (size_t)user_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (!_Py_Gid_Converter(args[1], &basegid)) {
         goto exit;
     }
@@ -12403,4 +12393,4 @@ exit:
 #ifndef OS_WAITSTATUS_TO_EXITCODE_METHODDEF
     #define OS_WAITSTATUS_TO_EXITCODE_METHODDEF
 #endif /* !defined(OS_WAITSTATUS_TO_EXITCODE_METHODDEF) */
-/*[clinic end generated code: output=a05abdc48e3def44 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=a377982a6d1e77b9 input=a9049054013a1b77]*/
diff --git a/Modules/clinic/pyexpat.c.h b/Modules/clinic/pyexpat.c.h
index a5b93e68598..4fac03ebaf2 100644
--- a/Modules/clinic/pyexpat.c.h
+++ b/Modules/clinic/pyexpat.c.h
@@ -129,15 +129,10 @@ pyexpat_xmlparser_SetBase(xmlparseobject *self, PyObject *arg)
         _PyArg_BadArgument("SetBase", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t base_length;
-    base = PyUnicode_AsUTF8AndSize(arg, &base_length);
+    base = PyUnicode_AsUTF8(arg);
     if (base == NULL) {
         goto exit;
     }
-    if (strlen(base) != (size_t)base_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = pyexpat_xmlparser_SetBase_impl(self, base);
 
 exit:
@@ -228,15 +223,10 @@ pyexpat_xmlparser_ExternalEntityParserCreate(xmlparseobject *self, PyTypeObject
         context = NULL;
     }
     else if (PyUnicode_Check(args[0])) {
-        Py_ssize_t context_length;
-        context = PyUnicode_AsUTF8AndSize(args[0], &context_length);
+        context = PyUnicode_AsUTF8(args[0]);
         if (context == NULL) {
             goto exit;
         }
-        if (strlen(context) != (size_t)context_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("ExternalEntityParserCreate", "argument 1", "str or None", args[0]);
@@ -249,15 +239,10 @@ pyexpat_xmlparser_ExternalEntityParserCreate(xmlparseobject *self, PyTypeObject
         _PyArg_BadArgument("ExternalEntityParserCreate", "argument 2", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t encoding_length;
-    encoding = PyUnicode_AsUTF8AndSize(args[1], &encoding_length);
+    encoding = PyUnicode_AsUTF8(args[1]);
     if (encoding == NULL) {
         goto exit;
     }
-    if (strlen(encoding) != (size_t)encoding_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_posonly:
     return_value = pyexpat_xmlparser_ExternalEntityParserCreate_impl(self, cls, context, encoding);
 
@@ -418,15 +403,10 @@ pyexpat_ParserCreate(PyObject *module, PyObject *const *args, Py_ssize_t nargs,
             encoding = NULL;
         }
         else if (PyUnicode_Check(args[0])) {
-            Py_ssize_t encoding_length;
-            encoding = PyUnicode_AsUTF8AndSize(args[0], &encoding_length);
+            encoding = PyUnicode_AsUTF8(args[0]);
             if (encoding == NULL) {
                 goto exit;
             }
-            if (strlen(encoding) != (size_t)encoding_length) {
-                PyErr_SetString(PyExc_ValueError, "embedded null character");
-                goto exit;
-            }
         }
         else {
             _PyArg_BadArgument("ParserCreate", "argument 'encoding'", "str or None", args[0]);
@@ -441,15 +421,10 @@ pyexpat_ParserCreate(PyObject *module, PyObject *const *args, Py_ssize_t nargs,
             namespace_separator = NULL;
         }
         else if (PyUnicode_Check(args[1])) {
-            Py_ssize_t namespace_separator_length;
-            namespace_separator = PyUnicode_AsUTF8AndSize(args[1], &namespace_separator_length);
+            namespace_separator = PyUnicode_AsUTF8(args[1]);
             if (namespace_separator == NULL) {
                 goto exit;
             }
-            if (strlen(namespace_separator) != (size_t)namespace_separator_length) {
-                PyErr_SetString(PyExc_ValueError, "embedded null character");
-                goto exit;
-            }
         }
         else {
             _PyArg_BadArgument("ParserCreate", "argument 'namespace_separator'", "str or None", args[1]);
@@ -498,4 +473,4 @@ exit:
 #ifndef PYEXPAT_XMLPARSER_USEFOREIGNDTD_METHODDEF
     #define PYEXPAT_XMLPARSER_USEFOREIGNDTD_METHODDEF
 #endif /* !defined(PYEXPAT_XMLPARSER_USEFOREIGNDTD_METHODDEF) */
-/*[clinic end generated code: output=48c4296e43777df4 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=bfc1f3d3e2cbc8dc input=a9049054013a1b77]*/
diff --git a/Modules/clinic/symtablemodule.c.h b/Modules/clinic/symtablemodule.c.h
index 2ecd3afc00d..d624c22cf28 100644
--- a/Modules/clinic/symtablemodule.c.h
+++ b/Modules/clinic/symtablemodule.c.h
@@ -36,18 +36,13 @@ _symtable_symtable(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
         _PyArg_BadArgument("symtable", "argument 3", "str", args[2]);
         goto exit;
     }
-    Py_ssize_t startstr_length;
-    startstr = PyUnicode_AsUTF8AndSize(args[2], &startstr_length);
+    startstr = PyUnicode_AsUTF8(args[2]);
     if (startstr == NULL) {
         goto exit;
     }
-    if (strlen(startstr) != (size_t)startstr_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = _symtable_symtable_impl(module, source, filename, startstr);
 
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=931964a76a72f850 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=9af1ab5a114a1ec7 input=a9049054013a1b77]*/
diff --git a/Objects/clinic/bytearrayobject.c.h b/Objects/clinic/bytearrayobject.c.h
index d95245067e2..355ae49ca74 100644
--- a/Objects/clinic/bytearrayobject.c.h
+++ b/Objects/clinic/bytearrayobject.c.h
@@ -68,15 +68,10 @@ bytearray___init__(PyObject *self, PyObject *args, PyObject *kwargs)
             _PyArg_BadArgument("bytearray", "argument 'encoding'", "str", fastargs[1]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(fastargs[1], &encoding_length);
+        encoding = PyUnicode_AsUTF8(fastargs[1]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -85,15 +80,10 @@ bytearray___init__(PyObject *self, PyObject *args, PyObject *kwargs)
         _PyArg_BadArgument("bytearray", "argument 'errors'", "str", fastargs[2]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(fastargs[2], &errors_length);
+    errors = PyUnicode_AsUTF8(fastargs[2]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = bytearray___init___impl((PyByteArrayObject *)self, arg, encoding, errors);
 
@@ -960,15 +950,10 @@ bytearray_decode(PyByteArrayObject *self, PyObject *const *args, Py_ssize_t narg
             _PyArg_BadArgument("decode", "argument 'encoding'", "str", args[0]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(args[0], &encoding_length);
+        encoding = PyUnicode_AsUTF8(args[0]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -977,15 +962,10 @@ bytearray_decode(PyByteArrayObject *self, PyObject *const *args, Py_ssize_t narg
         _PyArg_BadArgument("decode", "argument 'errors'", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+    errors = PyUnicode_AsUTF8(args[1]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = bytearray_decode_impl(self, encoding, errors);
 
@@ -1261,4 +1241,4 @@ bytearray_sizeof(PyByteArrayObject *self, PyObject *Py_UNUSED(ignored))
 {
     return bytearray_sizeof_impl(self);
 }
-/*[clinic end generated code: output=0797a5e03cda2a16 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=5a7de6295a7ce6cc input=a9049054013a1b77]*/
diff --git a/Objects/clinic/bytesobject.c.h b/Objects/clinic/bytesobject.c.h
index 1e45be3e7ae..042d0bf86e4 100644
--- a/Objects/clinic/bytesobject.c.h
+++ b/Objects/clinic/bytesobject.c.h
@@ -720,15 +720,10 @@ bytes_decode(PyBytesObject *self, PyObject *const *args, Py_ssize_t nargs, PyObj
             _PyArg_BadArgument("decode", "argument 'encoding'", "str", args[0]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(args[0], &encoding_length);
+        encoding = PyUnicode_AsUTF8(args[0]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -737,15 +732,10 @@ bytes_decode(PyBytesObject *self, PyObject *const *args, Py_ssize_t nargs, PyObj
         _PyArg_BadArgument("decode", "argument 'errors'", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+    errors = PyUnicode_AsUTF8(args[1]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = bytes_decode_impl(self, encoding, errors);
 
@@ -997,15 +987,10 @@ bytes_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
             _PyArg_BadArgument("bytes", "argument 'encoding'", "str", fastargs[1]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(fastargs[1], &encoding_length);
+        encoding = PyUnicode_AsUTF8(fastargs[1]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -1014,19 +999,14 @@ bytes_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         _PyArg_BadArgument("bytes", "argument 'errors'", "str", fastargs[2]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(fastargs[2], &errors_length);
+    errors = PyUnicode_AsUTF8(fastargs[2]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = bytes_new_impl(type, x, encoding, errors);
 
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=8a49dbbd78914a6f input=a9049054013a1b77]*/
+/*[clinic end generated code: output=97aab3f6ae398664 input=a9049054013a1b77]*/
diff --git a/Objects/clinic/floatobject.c.h b/Objects/clinic/floatobject.c.h
index 10f6149cc88..8c331197f05 100644
--- a/Objects/clinic/floatobject.c.h
+++ b/Objects/clinic/floatobject.c.h
@@ -275,15 +275,10 @@ float___getformat__(PyTypeObject *type, PyObject *arg)
         _PyArg_BadArgument("__getformat__", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t typestr_length;
-    typestr = PyUnicode_AsUTF8AndSize(arg, &typestr_length);
+    typestr = PyUnicode_AsUTF8(arg);
     if (typestr == NULL) {
         goto exit;
     }
-    if (strlen(typestr) != (size_t)typestr_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = float___getformat___impl(type, typestr);
 
 exit:
@@ -318,4 +313,4 @@ float___format__(PyObject *self, PyObject *arg)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=c79743c8551c30d9 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=01f6fbd082eefead input=a9049054013a1b77]*/
diff --git a/Objects/clinic/memoryobject.c.h b/Objects/clinic/memoryobject.c.h
index f199434dacb..ebc1e0617bd 100644
--- a/Objects/clinic/memoryobject.c.h
+++ b/Objects/clinic/memoryobject.c.h
@@ -305,15 +305,10 @@ memoryview_tobytes(PyMemoryViewObject *self, PyObject *const *args, Py_ssize_t n
         order = NULL;
     }
     else if (PyUnicode_Check(args[0])) {
-        Py_ssize_t order_length;
-        order = PyUnicode_AsUTF8AndSize(args[0], &order_length);
+        order = PyUnicode_AsUTF8(args[0]);
         if (order == NULL) {
             goto exit;
         }
-        if (strlen(order) != (size_t)order_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
     }
     else {
         _PyArg_BadArgument("tobytes", "argument 'order'", "str or None", args[0]);
@@ -413,4 +408,4 @@ skip_optional_pos:
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=7e76a09106921ba2 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=abd8c0ce804d8992 input=a9049054013a1b77]*/
diff --git a/Objects/clinic/unicodeobject.c.h b/Objects/clinic/unicodeobject.c.h
index 7711434f17c..83e3bf22989 100644
--- a/Objects/clinic/unicodeobject.c.h
+++ b/Objects/clinic/unicodeobject.c.h
@@ -203,15 +203,10 @@ unicode_encode(PyObject *self, PyObject *const *args, Py_ssize_t nargs, PyObject
             _PyArg_BadArgument("encode", "argument 'encoding'", "str", args[0]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(args[0], &encoding_length);
+        encoding = PyUnicode_AsUTF8(args[0]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -220,15 +215,10 @@ unicode_encode(PyObject *self, PyObject *const *args, Py_ssize_t nargs, PyObject
         _PyArg_BadArgument("encode", "argument 'errors'", "str", args[1]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(args[1], &errors_length);
+    errors = PyUnicode_AsUTF8(args[1]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = unicode_encode_impl(self, encoding, errors);
 
@@ -1473,15 +1463,10 @@ unicode_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
             _PyArg_BadArgument("str", "argument 'encoding'", "str", fastargs[1]);
             goto exit;
         }
-        Py_ssize_t encoding_length;
-        encoding = PyUnicode_AsUTF8AndSize(fastargs[1], &encoding_length);
+        encoding = PyUnicode_AsUTF8(fastargs[1]);
         if (encoding == NULL) {
             goto exit;
         }
-        if (strlen(encoding) != (size_t)encoding_length) {
-            PyErr_SetString(PyExc_ValueError, "embedded null character");
-            goto exit;
-        }
         if (!--noptargs) {
             goto skip_optional_pos;
         }
@@ -1490,19 +1475,14 @@ unicode_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         _PyArg_BadArgument("str", "argument 'errors'", "str", fastargs[2]);
         goto exit;
     }
-    Py_ssize_t errors_length;
-    errors = PyUnicode_AsUTF8AndSize(fastargs[2], &errors_length);
+    errors = PyUnicode_AsUTF8(fastargs[2]);
     if (errors == NULL) {
         goto exit;
     }
-    if (strlen(errors) != (size_t)errors_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_pos:
     return_value = unicode_new_impl(type, x, encoding, errors);
 
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=873d8b3d09af3095 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=20313d6339272ddc input=a9049054013a1b77]*/
diff --git a/Python/clinic/Python-tokenize.c.h b/Python/clinic/Python-tokenize.c.h
index 730fa8ef2a2..7417020d94c 100644
--- a/Python/clinic/Python-tokenize.c.h
+++ b/Python/clinic/Python-tokenize.c.h
@@ -65,19 +65,14 @@ tokenizeriter_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
         _PyArg_BadArgument("tokenizeriter", "argument 'encoding'", "str", fastargs[2]);
         goto exit;
     }
-    Py_ssize_t encoding_length;
-    encoding = PyUnicode_AsUTF8AndSize(fastargs[2], &encoding_length);
+    encoding = PyUnicode_AsUTF8(fastargs[2]);
     if (encoding == NULL) {
         goto exit;
     }
-    if (strlen(encoding) != (size_t)encoding_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
 skip_optional_kwonly:
     return_value = tokenizeriter_new_impl(type, readline, extra_tokens, encoding);
 
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=dcd6ec48f06a092e input=a9049054013a1b77]*/
+/*[clinic end generated code: output=92cb8176149f0924 input=a9049054013a1b77]*/
diff --git a/Python/clinic/bltinmodule.c.h b/Python/clinic/bltinmodule.c.h
index 8d40e659b54..4fb06bd0dba 100644
--- a/Python/clinic/bltinmodule.c.h
+++ b/Python/clinic/bltinmodule.c.h
@@ -329,15 +329,10 @@ builtin_compile(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObj
         _PyArg_BadArgument("compile", "argument 'mode'", "str", args[2]);
         goto exit;
     }
-    Py_ssize_t mode_length;
-    mode = PyUnicode_AsUTF8AndSize(args[2], &mode_length);
+    mode = PyUnicode_AsUTF8(args[2]);
     if (mode == NULL) {
         goto exit;
     }
-    if (strlen(mode) != (size_t)mode_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     if (!noptargs) {
         goto skip_optional_pos;
     }
@@ -1212,4 +1207,4 @@ builtin_issubclass(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=31bded5d08647a57 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=95d3813b1798f018 input=a9049054013a1b77]*/
diff --git a/Python/clinic/sysmodule.c.h b/Python/clinic/sysmodule.c.h
index 98717ecc875..571a34bd4a6 100644
--- a/Python/clinic/sysmodule.c.h
+++ b/Python/clinic/sysmodule.c.h
@@ -1259,15 +1259,10 @@ sys_activate_stack_trampoline(PyObject *module, PyObject *arg)
         _PyArg_BadArgument("activate_stack_trampoline", "argument", "str", arg);
         goto exit;
     }
-    Py_ssize_t backend_length;
-    backend = PyUnicode_AsUTF8AndSize(arg, &backend_length);
+    backend = PyUnicode_AsUTF8(arg);
     if (backend == NULL) {
         goto exit;
     }
-    if (strlen(backend) != (size_t)backend_length) {
-        PyErr_SetString(PyExc_ValueError, "embedded null character");
-        goto exit;
-    }
     return_value = sys_activate_stack_trampoline_impl(module, backend);
 
 exit:
@@ -1452,4 +1447,4 @@ exit:
 #ifndef SYS_GETANDROIDAPILEVEL_METHODDEF
     #define SYS_GETANDROIDAPILEVEL_METHODDEF
 #endif /* !defined(SYS_GETANDROIDAPILEVEL_METHODDEF) */
-/*[clinic end generated code: output=f36d45c829250775 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=cdfb714878deeaf1 input=a9049054013a1b77]*/
diff --git a/Tools/clinic/clinic.py b/Tools/clinic/clinic.py
index 5f94b90ae09..4f238a3dc0d 100755
--- a/Tools/clinic/clinic.py
+++ b/Tools/clinic/clinic.py
@@ -4350,34 +4350,23 @@ class str_converter(CConverter):
                     {bad_argument}
                     goto exit;
                 }}}}
-                Py_ssize_t {length_name};
-                {paramname} = PyUnicode_AsUTF8AndSize({argname}, &{length_name});
+                {paramname} = PyUnicode_AsUTF8({argname});
                 if ({paramname} == NULL) {{{{
                     goto exit;
                 }}}}
-                if (strlen({paramname}) != (size_t){length_name}) {{{{
-                    PyErr_SetString(PyExc_ValueError, "embedded null character");
-                    goto exit;
-                }}}}
                 """,
                 argname=argname,
-                bad_argument=self.bad_argument(displayname, 'str', limited_capi=limited_capi),
-                length_name=self.length_name)
+                bad_argument=self.bad_argument(displayname, 'str', limited_capi=limited_capi))
         if self.format_unit == 'z':
             return self.format_code("""
                 if ({argname} == Py_None) {{{{
                     {paramname} = NULL;
                 }}}}
                 else if (PyUnicode_Check({argname})) {{{{
-                    Py_ssize_t {length_name};
-                    {paramname} = PyUnicode_AsUTF8AndSize({argname}, &{length_name});
+                    {paramname} = PyUnicode_AsUTF8({argname});
                     if ({paramname} == NULL) {{{{
                         goto exit;
                     }}}}
-                    if (strlen({paramname}) != (size_t){length_name}) {{{{
-                        PyErr_SetString(PyExc_ValueError, "embedded null character");
-                        goto exit;
-                    }}}}
                 }}}}
                 else {{{{
                     {bad_argument}
@@ -4385,8 +4374,7 @@ class str_converter(CConverter):
                 }}}}
                 """,
                 argname=argname,
-                bad_argument=self.bad_argument(displayname, 'str or None', limited_capi=limited_capi),
-                length_name=self.length_name)
+                bad_argument=self.bad_argument(displayname, 'str or None', limited_capi=limited_capi))
         return super().parse_arg(argname, displayname, limited_capi=limited_capi)
 
 #