diff --git a/Include/internal/pycore_pylifecycle.h b/Include/internal/pycore_pylifecycle.h
index 1c475b1b118..da4af473296 100644
--- a/Include/internal/pycore_pylifecycle.h
+++ b/Include/internal/pycore_pylifecycle.h
@@ -21,7 +21,7 @@ extern int _Py_SetFileSystemEncoding(
     const char *encoding,
     const char *errors);
 extern void _Py_ClearFileSystemEncoding(void);
-extern PyStatus _PyUnicode_InitEncodings(PyInterpreterState *interp);
+extern PyStatus _PyUnicode_InitEncodings(PyThreadState *tstate);
 #ifdef MS_WINDOWS
 extern int _PyUnicode_EnableLegacyWindowsFSEncoding(void);
 #endif
@@ -37,20 +37,20 @@ extern int _PyStructSequence_Init(void);
 extern int _PyLong_Init(void);
 extern PyStatus _PyFaulthandler_Init(int enable);
 extern int _PyTraceMalloc_Init(int enable);
-extern PyObject * _PyBuiltin_Init(void);
+extern PyObject * _PyBuiltin_Init(PyThreadState *tstate);
 extern PyStatus _PySys_Create(
     _PyRuntimeState *runtime,
-    PyInterpreterState *interp,
+    PyThreadState *tstate,
     PyObject **sysmod_p);
 extern PyStatus _PySys_SetPreliminaryStderr(PyObject *sysdict);
 extern int _PySys_InitMain(
     _PyRuntimeState *runtime,
     PyThreadState *tstate);
-extern PyStatus _PyImport_Init(PyInterpreterState *interp);
+extern PyStatus _PyImport_Init(PyThreadState *tstate);
 extern PyStatus _PyExc_Init(void);
 extern PyStatus _PyErr_Init(void);
 extern PyStatus _PyBuiltins_AddExceptions(PyObject * bltinmod);
-extern PyStatus _PyImportHooks_Init(void);
+extern PyStatus _PyImportHooks_Init(PyThreadState *tstate);
 extern int _PyFloat_Init(void);
 extern PyStatus _Py_HashRandomization_Init(const PyConfig *);
 
@@ -88,7 +88,6 @@ extern void _PyWarnings_Fini(PyInterpreterState *interp);
 
 extern void _PyGILState_Init(
     _PyRuntimeState *runtime,
-    PyInterpreterState *interp,
     PyThreadState *tstate);
 extern void _PyGILState_Fini(_PyRuntimeState *runtime);
 
diff --git a/Include/internal/pycore_pystate.h b/Include/internal/pycore_pystate.h
index 3bfbc272ee1..68a72d82968 100644
--- a/Include/internal/pycore_pystate.h
+++ b/Include/internal/pycore_pystate.h
@@ -310,7 +310,7 @@ PyAPI_FUNC(PyThreadState *) _PyThreadState_Swap(
 PyAPI_FUNC(PyStatus) _PyInterpreterState_Enable(_PyRuntimeState *runtime);
 PyAPI_FUNC(void) _PyInterpreterState_DeleteExceptMain(_PyRuntimeState *runtime);
 
-/* Used by PyImport_Cleanup() */
+/* Used by _PyImport_Cleanup() */
 extern void _PyInterpreterState_ClearModules(PyInterpreterState *interp);
 
 PyAPI_FUNC(void) _PyGILState_Reinit(_PyRuntimeState *runtime);
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 6ec4127ff38..4f836259059 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -15792,8 +15792,10 @@ init_fs_encoding(PyInterpreterState *interp)
 
 
 PyStatus
-_PyUnicode_InitEncodings(PyInterpreterState *interp)
+_PyUnicode_InitEncodings(PyThreadState *tstate)
 {
+    PyInterpreterState *interp = tstate->interp;
+
     PyStatus status = init_fs_encoding(interp);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index c3e30593475..ae2a5187d98 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2769,11 +2769,11 @@ static struct PyModuleDef builtinsmodule = {
 
 
 PyObject *
-_PyBuiltin_Init(void)
+_PyBuiltin_Init(PyThreadState *tstate)
 {
     PyObject *mod, *dict, *debug;
 
-    const PyConfig *config = &_PyInterpreterState_GET_UNSAFE()->config;
+    const PyConfig *config = &tstate->interp->config;
 
     if (PyType_Ready(&PyFilter_Type) < 0 ||
         PyType_Ready(&PyMap_Type) < 0 ||
diff --git a/Python/import.c b/Python/import.c
index dc0d5b8b901..3937fbe37d9 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -48,8 +48,9 @@ module _imp
 /* Initialize things */
 
 PyStatus
-_PyImport_Init(PyInterpreterState *interp)
+_PyImport_Init(PyThreadState *tstate)
 {
+    PyInterpreterState *interp = tstate->interp;
     interp->builtins_copy = PyDict_Copy(interp->builtins);
     if (interp->builtins_copy == NULL) {
         return _PyStatus_ERR("Can't backup builtins dict");
@@ -58,7 +59,7 @@ _PyImport_Init(PyInterpreterState *interp)
 }
 
 PyStatus
-_PyImportHooks_Init(void)
+_PyImportHooks_Init(PyThreadState *tstate)
 {
     PyObject *v, *path_hooks = NULL;
     int err = 0;
@@ -89,7 +90,7 @@ _PyImportHooks_Init(void)
     return _PyStatus_OK();
 
   error:
-    PyErr_Print();
+    _PyErr_Print(tstate);
     return _PyStatus_ERR("initializing sys.meta_path, sys.path_hooks, "
                         "or path_importer_cache failed");
 }
@@ -554,7 +555,7 @@ _PyImport_Cleanup(PyThreadState *tstate)
     }
     Py_XDECREF(dict);
     /* Clear module dict copies stored in the interpreter state */
-    _PyInterpreterState_ClearModules(tstate->interp);
+    _PyInterpreterState_ClearModules(interp);
     /* Collect references */
     _PyGC_CollectNoFail();
     /* Dump GC stats before it's too late, since it uses the warnings
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index c0b34507899..10765dab8f5 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -11,6 +11,7 @@
 #include "pycore_fileutils.h"
 #include "pycore_hamt.h"
 #include "pycore_pathconfig.h"
+#include "pycore_pyerrors.h"
 #include "pycore_pylifecycle.h"
 #include "pycore_pymem.h"
 #include "pycore_pystate.h"
@@ -60,13 +61,13 @@ extern "C" {
 
 extern grammar _PyParser_Grammar; /* From graminit.c */
 
-/* Forward */
+/* Forward declarations */
 static PyStatus add_main_module(PyInterpreterState *interp);
-static PyStatus init_import_size(void);
-static PyStatus init_sys_streams(PyInterpreterState *interp);
-static PyStatus init_signals(void);
-static void call_py_exitfuncs(PyInterpreterState *);
-static void wait_for_thread_shutdown(void);
+static PyStatus init_import_site(void);
+static PyStatus init_sys_streams(PyThreadState *tstate);
+static PyStatus init_signals(PyThreadState *tstate);
+static void call_py_exitfuncs(PyThreadState *tstate);
+static void wait_for_thread_shutdown(PyThreadState *tstate);
 static void call_ll_exitfuncs(_PyRuntimeState *runtime);
 
 int _Py_UnhandledKeyboardInterrupt = 0;
@@ -147,11 +148,12 @@ Py_IsInitialized(void)
 */
 
 static PyStatus
-init_importlib(PyInterpreterState *interp, PyObject *sysmod)
+init_importlib(PyThreadState *tstate, PyObject *sysmod)
 {
     PyObject *importlib;
     PyObject *impmod;
     PyObject *value;
+    PyInterpreterState *interp = tstate->interp;
     int verbose = interp->config.verbose;
 
     /* Import _importlib through its frozen version, _frozen_importlib. */
@@ -188,7 +190,7 @@ init_importlib(PyInterpreterState *interp, PyObject *sysmod)
     /* Install importlib as the implementation of import */
     value = PyObject_CallMethod(importlib, "_install", "OO", sysmod, impmod);
     if (value == NULL) {
-        PyErr_Print();
+        _PyErr_Print(tstate);
         return _PyStatus_ERR("importlib install failed");
     }
     Py_DECREF(value);
@@ -204,7 +206,7 @@ init_importlib_external(PyThreadState *tstate)
     value = PyObject_CallMethod(tstate->interp->importlib,
                                 "_install_external_importers", "");
     if (value == NULL) {
-        PyErr_Print();
+        _PyErr_Print(tstate);
         return _PyStatus_ERR("external importer setup failed");
     }
     Py_DECREF(value);
@@ -449,7 +451,7 @@ _Py_SetLocaleFromEnv(int category)
 
 static PyStatus
 pyinit_core_reconfigure(_PyRuntimeState *runtime,
-                        PyInterpreterState **interp_p,
+                        PyThreadState **tstate_p,
                         const PyConfig *config)
 {
     PyStatus status;
@@ -457,12 +459,12 @@ pyinit_core_reconfigure(_PyRuntimeState *runtime,
     if (!tstate) {
         return _PyStatus_ERR("failed to read thread state");
     }
+    *tstate_p = tstate;
 
     PyInterpreterState *interp = tstate->interp;
     if (interp == NULL) {
         return _PyStatus_ERR("can't make main interpreter");
     }
-    *interp_p = interp;
 
     _PyConfig_Write(config, runtime);
 
@@ -519,23 +521,22 @@ pycore_init_runtime(_PyRuntimeState *runtime,
 static PyStatus
 pycore_create_interpreter(_PyRuntimeState *runtime,
                           const PyConfig *config,
-                          PyInterpreterState **interp_p)
+                          PyThreadState **tstate_p)
 {
     PyInterpreterState *interp = PyInterpreterState_New();
     if (interp == NULL) {
         return _PyStatus_ERR("can't make main interpreter");
     }
-    *interp_p = interp;
 
     PyStatus status = _PyConfig_Copy(&interp->config, config);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
-    config = &interp->config;
 
     PyThreadState *tstate = PyThreadState_New(interp);
-    if (tstate == NULL)
+    if (tstate == NULL) {
         return _PyStatus_ERR("can't make first thread");
+    }
     (void) PyThreadState_Swap(tstate);
 
     /* We can't call _PyEval_FiniThreads() in Py_FinalizeEx because
@@ -546,11 +547,12 @@ pycore_create_interpreter(_PyRuntimeState *runtime,
     _PyEval_FiniThreads(&runtime->ceval);
 
     /* Auto-thread-state API */
-    _PyGILState_Init(runtime, interp, tstate);
+    _PyGILState_Init(runtime, tstate);
 
     /* Create the GIL */
     PyEval_InitThreads();
 
+    *tstate_p = tstate;
     return _PyStatus_OK();
 }
 
@@ -599,9 +601,11 @@ pycore_init_types(void)
 
 
 static PyStatus
-pycore_init_builtins(PyInterpreterState *interp)
+pycore_init_builtins(PyThreadState *tstate)
 {
-    PyObject *bimod = _PyBuiltin_Init();
+    PyInterpreterState *interp = tstate->interp;
+
+    PyObject *bimod = _PyBuiltin_Init(tstate);
     if (bimod == NULL) {
         return _PyStatus_ERR("can't initialize builtins modules");
     }
@@ -622,14 +626,16 @@ pycore_init_builtins(PyInterpreterState *interp)
 
 
 static PyStatus
-pycore_init_import_warnings(PyInterpreterState *interp, PyObject *sysmod)
+pycore_init_import_warnings(PyThreadState *tstate, PyObject *sysmod)
 {
-    PyStatus status = _PyImport_Init(interp);
+    const PyConfig *config = &tstate->interp->config;
+
+    PyStatus status = _PyImport_Init(tstate);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
 
-    status = _PyImportHooks_Init();
+    status = _PyImportHooks_Init(tstate);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
@@ -639,16 +645,16 @@ pycore_init_import_warnings(PyInterpreterState *interp, PyObject *sysmod)
         return _PyStatus_ERR("can't initialize warnings");
     }
 
-    if (interp->config._install_importlib) {
-        status = _PyConfig_SetPathConfig(&interp->config);
+    if (config->_install_importlib) {
+        status = _PyConfig_SetPathConfig(config);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
     }
 
     /* This call sets up builtin and frozen import support */
-    if (interp->config._install_importlib) {
-        status = init_importlib(interp, sysmod);
+    if (config->_install_importlib) {
+        status = init_importlib(tstate, sysmod);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
@@ -659,11 +665,9 @@ pycore_init_import_warnings(PyInterpreterState *interp, PyObject *sysmod)
 
 static PyStatus
 pyinit_config(_PyRuntimeState *runtime,
-              PyInterpreterState **interp_p,
+              PyThreadState **tstate_p,
               const PyConfig *config)
 {
-    PyInterpreterState *interp;
-
     _PyConfig_Write(config, runtime);
 
     PyStatus status = pycore_init_runtime(runtime, config);
@@ -671,12 +675,13 @@ pyinit_config(_PyRuntimeState *runtime,
         return status;
     }
 
-    status = pycore_create_interpreter(runtime, config, &interp);
+    PyThreadState *tstate;
+    status = pycore_create_interpreter(runtime, config, &tstate);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
-    config = &interp->config;
-    *interp_p = interp;
+    config = &tstate->interp->config;
+    *tstate_p = tstate;
 
     status = pycore_init_types();
     if (_PyStatus_EXCEPTION(status)) {
@@ -684,17 +689,17 @@ pyinit_config(_PyRuntimeState *runtime,
     }
 
     PyObject *sysmod;
-    status = _PySys_Create(runtime, interp, &sysmod);
+    status = _PySys_Create(runtime, tstate, &sysmod);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
 
-    status = pycore_init_builtins(interp);
+    status = pycore_init_builtins(tstate);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
 
-    status = pycore_init_import_warnings(interp, sysmod);
+    status = pycore_init_import_warnings(tstate, sysmod);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
@@ -822,7 +827,7 @@ _Py_PreInitializeFromConfig(const PyConfig *config,
 static PyStatus
 pyinit_core(_PyRuntimeState *runtime,
             const PyConfig *src_config,
-            PyInterpreterState **interp_p)
+            PyThreadState **tstate_p)
 {
     PyStatus status;
 
@@ -845,10 +850,10 @@ pyinit_core(_PyRuntimeState *runtime,
     }
 
     if (!runtime->core_initialized) {
-        status = pyinit_config(runtime, interp_p, &config);
+        status = pyinit_config(runtime, tstate_p, &config);
     }
     else {
-        status = pyinit_core_reconfigure(runtime, interp_p, &config);
+        status = pyinit_core_reconfigure(runtime, tstate_p, &config);
     }
     if (_PyStatus_EXCEPTION(status)) {
         goto done;
@@ -893,14 +898,14 @@ _Py_ReconfigureMainInterpreter(PyInterpreterState *interp)
  * non-zero return code.
  */
 static PyStatus
-pyinit_main(_PyRuntimeState *runtime, PyInterpreterState *interp)
+pyinit_main(_PyRuntimeState *runtime, PyThreadState *tstate)
 {
     if (!runtime->core_initialized) {
         return _PyStatus_ERR("runtime core not initialized");
     }
 
     /* Configure the main interpreter */
-    PyThreadState *tstate = _PyRuntimeState_GetThreadState(runtime);
+    PyInterpreterState *interp = tstate->interp;
     PyConfig *config = &interp->config;
 
     if (runtime->initialized) {
@@ -936,13 +941,13 @@ pyinit_main(_PyRuntimeState *runtime, PyInterpreterState *interp)
         return status;
     }
 
-    status = _PyUnicode_InitEncodings(interp);
+    status = _PyUnicode_InitEncodings(tstate);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
 
     if (config->install_signal_handlers) {
-        status = init_signals();
+        status = init_signals(tstate);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
@@ -957,7 +962,7 @@ pyinit_main(_PyRuntimeState *runtime, PyInterpreterState *interp)
         return status;
     }
 
-    status = init_sys_streams(interp);
+    status = init_sys_streams(tstate);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
@@ -969,7 +974,7 @@ pyinit_main(_PyRuntimeState *runtime, PyInterpreterState *interp)
         PyObject *warnings_module = PyImport_ImportModule("warnings");
         if (warnings_module == NULL) {
             fprintf(stderr, "'import warnings' failed; traceback:\n");
-            PyErr_Print();
+            _PyErr_Print(tstate);
         }
         Py_XDECREF(warnings_module);
     }
@@ -977,7 +982,7 @@ pyinit_main(_PyRuntimeState *runtime, PyInterpreterState *interp)
     runtime->initialized = 1;
 
     if (config->site_import) {
-        status = init_import_size(); /* Module site */
+        status = init_import_site();
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
@@ -999,9 +1004,8 @@ _Py_InitializeMain(void)
         return status;
     }
     _PyRuntimeState *runtime = &_PyRuntime;
-    PyInterpreterState *interp = _PyRuntimeState_GetThreadState(runtime)->interp;
-
-    return pyinit_main(runtime, interp);
+    PyThreadState *tstate = _PyRuntimeState_GetThreadState(runtime);
+    return pyinit_main(runtime, tstate);
 }
 
 
@@ -1020,15 +1024,15 @@ Py_InitializeFromConfig(const PyConfig *config)
     }
     _PyRuntimeState *runtime = &_PyRuntime;
 
-    PyInterpreterState *interp = NULL;
-    status = pyinit_core(runtime, config, &interp);
+    PyThreadState *tstate = NULL;
+    status = pyinit_core(runtime, config, &tstate);
     if (_PyStatus_EXCEPTION(status)) {
         return status;
     }
-    config = &interp->config;
+    config = &tstate->interp->config;
 
     if (config->_init_main) {
-        status = pyinit_main(runtime, interp);
+        status = pyinit_main(runtime, tstate);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
@@ -1148,16 +1152,16 @@ Py_FinalizeEx(void)
         return status;
     }
 
-    // Wrap up existing "threading"-module-created, non-daemon threads.
-    wait_for_thread_shutdown();
-
-    // Make any remaining pending calls.
-    _Py_FinishPendingCalls(runtime);
-
     /* Get current thread state and interpreter pointer */
     PyThreadState *tstate = _PyRuntimeState_GetThreadState(runtime);
     PyInterpreterState *interp = tstate->interp;
 
+    // Wrap up existing "threading"-module-created, non-daemon threads.
+    wait_for_thread_shutdown(tstate);
+
+    // Make any remaining pending calls.
+    _Py_FinishPendingCalls(runtime);
+
     /* The interpreter is still entirely intact at this point, and the
      * exit funcs may be relying on that.  In particular, if some thread
      * or exit func is still waiting to do an import, the import machinery
@@ -1168,7 +1172,7 @@ Py_FinalizeEx(void)
      * the threads created via Threading.
      */
 
-    call_py_exitfuncs(interp);
+    call_py_exitfuncs(tstate);
 
     /* Copy the core config, PyInterpreterState_Delete() free
        the core config memory */
@@ -1462,7 +1466,7 @@ new_interpreter(PyThreadState **tstate_p)
             return _PyStatus_ERR("can't finish initializing sys");
         }
     }
-    else if (PyErr_Occurred()) {
+    else if (_PyErr_Occurred(tstate)) {
         goto handle_error;
     }
 
@@ -1473,7 +1477,7 @@ new_interpreter(PyThreadState **tstate_p)
             goto handle_error;
         Py_INCREF(interp->builtins);
     }
-    else if (PyErr_Occurred()) {
+    else if (_PyErr_Occurred(tstate)) {
         goto handle_error;
     }
 
@@ -1488,12 +1492,12 @@ new_interpreter(PyThreadState **tstate_p)
             return status;
         }
 
-        status = _PyImportHooks_Init();
+        status = _PyImportHooks_Init(tstate);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
 
-        status = init_importlib(interp, sysmod);
+        status = init_importlib(tstate, sysmod);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
@@ -1503,12 +1507,12 @@ new_interpreter(PyThreadState **tstate_p)
             return status;
         }
 
-        status = _PyUnicode_InitEncodings(interp);
+        status = _PyUnicode_InitEncodings(tstate);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
 
-        status = init_sys_streams(interp);
+        status = init_sys_streams(tstate);
         if (_PyStatus_EXCEPTION(status)) {
             return status;
         }
@@ -1519,14 +1523,14 @@ new_interpreter(PyThreadState **tstate_p)
         }
 
         if (config->site_import) {
-            status = init_import_size();
+            status = init_import_site();
             if (_PyStatus_EXCEPTION(status)) {
                 return status;
             }
         }
     }
 
-    if (PyErr_Occurred()) {
+    if (_PyErr_Occurred(tstate)) {
         goto handle_error;
     }
 
@@ -1575,19 +1579,22 @@ Py_EndInterpreter(PyThreadState *tstate)
 {
     PyInterpreterState *interp = tstate->interp;
 
-    if (tstate != _PyThreadState_GET())
+    if (tstate != _PyThreadState_GET()) {
         Py_FatalError("Py_EndInterpreter: thread is not current");
-    if (tstate->frame != NULL)
+    }
+    if (tstate->frame != NULL) {
         Py_FatalError("Py_EndInterpreter: thread still has a frame");
+    }
     interp->finalizing = 1;
 
     // Wrap up existing "threading"-module-created, non-daemon threads.
-    wait_for_thread_shutdown();
+    wait_for_thread_shutdown(tstate);
 
-    call_py_exitfuncs(interp);
+    call_py_exitfuncs(tstate);
 
-    if (tstate != interp->tstate_head || tstate->next != NULL)
+    if (tstate != interp->tstate_head || tstate->next != NULL) {
         Py_FatalError("Py_EndInterpreter: not the last thread");
+    }
 
     _PyImport_Cleanup(tstate);
     PyInterpreterState_Clear(interp);
@@ -1648,7 +1655,7 @@ add_main_module(PyInterpreterState *interp)
 /* Import the site module (not into __main__ though) */
 
 static PyStatus
-init_import_size(void)
+init_import_site(void)
 {
     PyObject *m;
     m = PyImport_ImportModule("site");
@@ -1835,7 +1842,7 @@ error:
 
 /* Initialize sys.stdin, stdout, stderr and builtins.open */
 static PyStatus
-init_sys_streams(PyInterpreterState *interp)
+init_sys_streams(PyThreadState *tstate)
 {
     PyObject *iomod = NULL, *wrapper;
     PyObject *bimod = NULL;
@@ -1844,7 +1851,7 @@ init_sys_streams(PyInterpreterState *interp)
     int fd;
     PyObject * encoding_attr;
     PyStatus res = _PyStatus_OK();
-    PyConfig *config = &interp->config;
+    const PyConfig *config = &tstate->interp->config;
 
     /* Check that stdin is not a directory
        Using shell redirection, you can redirect stdin to a directory,
@@ -1935,7 +1942,7 @@ init_sys_streams(PyInterpreterState *interp)
         }
         Py_DECREF(encoding_attr);
     }
-    PyErr_Clear();  /* Not a fatal error if codec isn't available */
+    _PyErr_Clear(tstate);  /* Not a fatal error if codec isn't available */
 
     if (PySys_SetObject("__stderr__", std) < 0) {
         Py_DECREF(std);
@@ -1983,11 +1990,12 @@ _Py_FatalError_DumpTracebacks(int fd)
 static int
 _Py_FatalError_PrintExc(int fd)
 {
+    PyThreadState *tstate = _PyThreadState_GET();
     PyObject *ferr, *res;
     PyObject *exception, *v, *tb;
     int has_tb;
 
-    PyErr_Fetch(&exception, &v, &tb);
+    _PyErr_Fetch(tstate, &exception, &v, &tb);
     if (exception == NULL) {
         /* No current exception */
         return 0;
@@ -2000,7 +2008,7 @@ _Py_FatalError_PrintExc(int fd)
         return 0;
     }
 
-    PyErr_NormalizeException(&exception, &v, &tb);
+    _PyErr_NormalizeException(tstate, &exception, &v, &tb);
     if (tb == NULL) {
         tb = Py_None;
         Py_INCREF(tb);
@@ -2019,10 +2027,12 @@ _Py_FatalError_PrintExc(int fd)
 
     /* sys.stderr may be buffered: call sys.stderr.flush() */
     res = _PyObject_CallMethodId(ferr, &PyId_flush, NULL);
-    if (res == NULL)
-        PyErr_Clear();
-    else
+    if (res == NULL) {
+        _PyErr_Clear(tstate);
+    }
+    else {
         Py_DECREF(res);
+    }
 
     return has_tb;
 }
@@ -2173,7 +2183,7 @@ Py_ExitStatusException(PyStatus status)
 /* For the atexit module. */
 void _Py_PyAtExit(void (*func)(PyObject *), PyObject *module)
 {
-    PyInterpreterState *is = _PyInterpreterState_Get();
+    PyInterpreterState *is = _PyInterpreterState_GET_UNSAFE();
 
     /* Guard against API misuse (see bpo-17852) */
     assert(is->pyexitfunc == NULL || is->pyexitfunc == func);
@@ -2183,13 +2193,14 @@ void _Py_PyAtExit(void (*func)(PyObject *), PyObject *module)
 }
 
 static void
-call_py_exitfuncs(PyInterpreterState *istate)
+call_py_exitfuncs(PyThreadState *tstate)
 {
-    if (istate->pyexitfunc == NULL)
+    PyInterpreterState *interp = tstate->interp;
+    if (interp->pyexitfunc == NULL)
         return;
 
-    (*istate->pyexitfunc)(istate->pyexitmodule);
-    PyErr_Clear();
+    (*interp->pyexitfunc)(interp->pyexitmodule);
+    _PyErr_Clear(tstate);
 }
 
 /* Wait until threading._shutdown completes, provided
@@ -2197,13 +2208,13 @@ call_py_exitfuncs(PyInterpreterState *istate)
    The shutdown routine will wait until all non-daemon
    "threading" threads have completed. */
 static void
-wait_for_thread_shutdown(void)
+wait_for_thread_shutdown(PyThreadState *tstate)
 {
     _Py_IDENTIFIER(_shutdown);
     PyObject *result;
     PyObject *threading = _PyImport_GetModuleId(&PyId_threading);
     if (threading == NULL) {
-        if (PyErr_Occurred()) {
+        if (_PyErr_Occurred(tstate)) {
             PyErr_WriteUnraisable(NULL);
         }
         /* else: threading not imported */
@@ -2255,7 +2266,7 @@ Py_Exit(int sts)
 }
 
 static PyStatus
-init_signals(void)
+init_signals(PyThreadState *tstate)
 {
 #ifdef SIGPIPE
     PyOS_setsig(SIGPIPE, SIG_IGN);
@@ -2267,7 +2278,7 @@ init_signals(void)
     PyOS_setsig(SIGXFSZ, SIG_IGN);
 #endif
     PyOS_InitInterrupts(); /* May imply initsignal() */
-    if (PyErr_Occurred()) {
+    if (_PyErr_Occurred(tstate)) {
         return _PyStatus_ERR("can't import signal");
     }
     return _PyStatus_OK();
diff --git a/Python/pystate.c b/Python/pystate.c
index 1e2b4804589..503b4bf8549 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -1143,19 +1143,18 @@ PyThreadState_IsCurrent(PyThreadState *tstate)
    Py_Initialize/Py_FinalizeEx
 */
 void
-_PyGILState_Init(_PyRuntimeState *runtime,
-                 PyInterpreterState *interp, PyThreadState *tstate)
+_PyGILState_Init(_PyRuntimeState *runtime, PyThreadState *tstate)
 {
     /* must init with valid states */
-    assert(interp != NULL);
     assert(tstate != NULL);
+    assert(tstate->interp != NULL);
 
     struct _gilstate_runtime_state *gilstate = &runtime->gilstate;
 
     if (PyThread_tss_create(&gilstate->autoTSSkey) != 0) {
         Py_FatalError("Could not allocate TSS entry");
     }
-    gilstate->autoInterpreterState = interp;
+    gilstate->autoInterpreterState = tstate->interp;
     assert(PyThread_tss_get(&gilstate->autoTSSkey) == NULL);
     assert(tstate->gilstate_counter == 0);
 
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index fcbcb3b24d5..8da839c5a59 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -3036,10 +3036,10 @@ error:
 /* Create sys module without all attributes: _PySys_InitMain() should be called
    later to add remaining attributes. */
 PyStatus
-_PySys_Create(_PyRuntimeState *runtime, PyInterpreterState *interp,
+_PySys_Create(_PyRuntimeState *runtime, PyThreadState *tstate,
               PyObject **sysmod_p)
 {
-    PyThreadState *tstate = _PyRuntimeState_GetThreadState(runtime);
+    PyInterpreterState *interp = tstate->interp;
 
     PyObject *modules = PyDict_New();
     if (modules == NULL) {