diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 9e662f9368b..830b324a42b 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -4277,11 +4277,10 @@ Array_subscript(PyObject *myself, PyObject *item)
         PyObject *np;
         Py_ssize_t start, stop, step, slicelen, cur, i;
 
-        if (PySlice_GetIndicesEx(item,
-                                 self->b_length, &start, &stop,
-                                 &step, &slicelen) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelen = PySlice_AdjustIndices(self->b_length, &start, &stop, step);
 
         stgdict = PyObject_stgdict((PyObject *)self);
         assert(stgdict); /* Cannot be NULL for array object instances */
@@ -4418,11 +4417,10 @@ Array_ass_subscript(PyObject *myself, PyObject *item, PyObject *value)
     else if (PySlice_Check(item)) {
         Py_ssize_t start, stop, step, slicelen, otherlen, i, cur;
 
-        if (PySlice_GetIndicesEx(item,
-                                 self->b_length, &start, &stop,
-                                 &step, &slicelen) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return -1;
         }
+        slicelen = PySlice_AdjustIndices(self->b_length, &start, &stop, step);
         if ((step < 0 && start < stop) ||
             (step > 0 && start > stop))
             stop = start;
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index 4e1750f9dd0..456c4a2a799 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -1740,11 +1740,11 @@ element_subscr(PyObject* self_, PyObject* item)
         if (!self->extra)
             return PyList_New(0);
 
-        if (PySlice_GetIndicesEx(item,
-                self->extra->length,
-                &start, &stop, &step, &slicelen) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelen = PySlice_AdjustIndices(self->extra->length, &start, &stop,
+                                         step);
 
         if (slicelen <= 0)
             return PyList_New(0);
@@ -1796,11 +1796,11 @@ element_ass_subscr(PyObject* self_, PyObject* item, PyObject* value)
                 return -1;
         }
 
-        if (PySlice_GetIndicesEx(item,
-                self->extra->length,
-                &start, &stop, &step, &slicelen) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return -1;
         }
+        slicelen = PySlice_AdjustIndices(self->extra->length, &start, &stop,
+                                         step);
 
         if (value == NULL) {
             /* Delete slice */
diff --git a/Modules/_testbuffer.c b/Modules/_testbuffer.c
index 4e1ce6851a5..6b8ab34d931 100644
--- a/Modules/_testbuffer.c
+++ b/Modules/_testbuffer.c
@@ -1715,10 +1715,10 @@ init_slice(Py_buffer *base, PyObject *key, int dim)
 {
     Py_ssize_t start, stop, step, slicelength;
 
-    if (PySlice_GetIndicesEx(key, base->shape[dim],
-                             &start, &stop, &step, &slicelength) < 0) {
+    if (PySlice_Unpack(key, &start, &stop, &step) < 0) {
         return -1;
     }
+    slicelength = PySlice_AdjustIndices(base->shape[dim], &start, &stop, step);
 
 
     if (base->suboffsets == NULL || dim == 0) {
@@ -1935,9 +1935,10 @@ slice_indices(PyObject *self, PyObject *args)
             "first argument must be a slice object");
         return NULL;
     }
-    if (PySlice_GetIndicesEx(key, len, &s[0], &s[1], &s[2], &s[3]) < 0) {
+    if (PySlice_Unpack(key, &s[0], &s[1], &s[2]) < 0) {
         return NULL;
     }
+    s[3] = PySlice_AdjustIndices(len, &s[0], &s[1], s[2]);
 
     ret = PyTuple_New(4);
     if (ret == NULL)
diff --git a/Modules/arraymodule.c b/Modules/arraymodule.c
index e067b30b999..412e39e9513 100644
--- a/Modules/arraymodule.c
+++ b/Modules/arraymodule.c
@@ -2289,10 +2289,11 @@ array_subscr(arrayobject* self, PyObject* item)
         arrayobject* ar;
         int itemsize = self->ob_descr->itemsize;
 
-        if (PySlice_GetIndicesEx(item, Py_SIZE(self),
-                         &start, &stop, &step, &slicelength) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelength = PySlice_AdjustIndices(Py_SIZE(self), &start, &stop,
+                                            step);
 
         if (slicelength <= 0) {
             return newarrayobject(&Arraytype, 0, self->ob_descr);
@@ -2360,11 +2361,11 @@ array_ass_subscr(arrayobject* self, PyObject* item, PyObject* value)
             return (*self->ob_descr->setitem)(self, i, value);
     }
     else if (PySlice_Check(item)) {
-        if (PySlice_GetIndicesEx(item,
-                                 Py_SIZE(self), &start, &stop,
-                                 &step, &slicelength) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return -1;
         }
+        slicelength = PySlice_AdjustIndices(Py_SIZE(self), &start, &stop,
+                                            step);
     }
     else {
         PyErr_SetString(PyExc_TypeError,
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 56f44006704..49214a1defc 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -778,10 +778,10 @@ mmap_subscript(mmap_object *self, PyObject *item)
     else if (PySlice_Check(item)) {
         Py_ssize_t start, stop, step, slicelen;
 
-        if (PySlice_GetIndicesEx(item, self->size,
-                         &start, &stop, &step, &slicelen) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelen = PySlice_AdjustIndices(self->size, &start, &stop, step);
 
         if (slicelen <= 0)
             return PyBytes_FromStringAndSize("", 0);
@@ -904,11 +904,10 @@ mmap_ass_subscript(mmap_object *self, PyObject *item, PyObject *value)
         Py_ssize_t start, stop, step, slicelen;
         Py_buffer vbuf;
 
-        if (PySlice_GetIndicesEx(item,
-                                 self->size, &start, &stop,
-                                 &step, &slicelen) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return -1;
         }
+        slicelen = PySlice_AdjustIndices(self->size, &start, &stop, step);
         if (value == NULL) {
             PyErr_SetString(PyExc_TypeError,
                 "mmap object doesn't support slice deletion");
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index fe322d22b86..22dd810a7dd 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -400,11 +400,11 @@ bytearray_subscript(PyByteArrayObject *self, PyObject *index)
     }
     else if (PySlice_Check(index)) {
         Py_ssize_t start, stop, step, slicelength, cur, i;
-        if (PySlice_GetIndicesEx(index,
-                                 PyByteArray_GET_SIZE(self),
-                                 &start, &stop, &step, &slicelength) < 0) {
+        if (PySlice_Unpack(index, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelength = PySlice_AdjustIndices(PyByteArray_GET_SIZE(self),
+                                            &start, &stop, step);
 
         if (slicelength <= 0)
             return PyByteArray_FromStringAndSize("", 0);
@@ -630,11 +630,11 @@ bytearray_ass_subscript(PyByteArrayObject *self, PyObject *index, PyObject *valu
         }
     }
     else if (PySlice_Check(index)) {
-        if (PySlice_GetIndicesEx(index,
-                                 PyByteArray_GET_SIZE(self),
-                                 &start, &stop, &step, &slicelen) < 0) {
+        if (PySlice_Unpack(index, &start, &stop, &step) < 0) {
             return -1;
         }
+        slicelen = PySlice_AdjustIndices(PyByteArray_GET_SIZE(self), &start,
+                                         &stop, step);
     }
     else {
         PyErr_Format(PyExc_TypeError,
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index bde7948c109..e95ab9c63b1 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -1683,11 +1683,11 @@ bytes_subscript(PyBytesObject* self, PyObject* item)
         char* result_buf;
         PyObject* result;
 
-        if (PySlice_GetIndicesEx(item,
-                         PyBytes_GET_SIZE(self),
-                         &start, &stop, &step, &slicelength) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelength = PySlice_AdjustIndices(PyBytes_GET_SIZE(self), &start,
+                                            &stop, step);
 
         if (slicelength <= 0) {
             return PyBytes_FromStringAndSize("", 0);
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 9b42106e30b..314a13c4c8f 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -2486,10 +2486,11 @@ list_subscript(PyListObject* self, PyObject* item)
         PyObject* it;
         PyObject **src, **dest;
 
-        if (PySlice_GetIndicesEx(item, Py_SIZE(self),
-                         &start, &stop, &step, &slicelength) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelength = PySlice_AdjustIndices(Py_SIZE(self), &start, &stop,
+                                            step);
 
         if (slicelength <= 0) {
             return PyList_New(0);
@@ -2535,10 +2536,11 @@ list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value)
     else if (PySlice_Check(item)) {
         Py_ssize_t start, stop, step, slicelength;
 
-        if (PySlice_GetIndicesEx(item, Py_SIZE(self),
-                         &start, &stop, &step, &slicelength) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return -1;
         }
+        slicelength = PySlice_AdjustIndices(Py_SIZE(self), &start, &stop,
+                                            step);
 
         if (step == 1)
             return list_ass_slice(self, start, stop, value);
diff --git a/Objects/memoryobject.c b/Objects/memoryobject.c
index 8a2316333b0..1b95af2d4a8 100644
--- a/Objects/memoryobject.c
+++ b/Objects/memoryobject.c
@@ -2285,10 +2285,10 @@ init_slice(Py_buffer *base, PyObject *key, int dim)
 {
     Py_ssize_t start, stop, step, slicelength;
 
-    if (PySlice_GetIndicesEx(key, base->shape[dim],
-                             &start, &stop, &step, &slicelength) < 0) {
+    if (PySlice_Unpack(key, &start, &stop, &step) < 0) {
         return -1;
     }
+    slicelength = PySlice_AdjustIndices(base->shape[dim], &start, &stop, step);
 
 
     if (base->suboffsets == NULL || dim == 0) {
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 55da0e3a2bb..2a904904993 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -758,11 +758,11 @@ tuplesubscript(PyTupleObject* self, PyObject* item)
         PyObject* it;
         PyObject **src, **dest;
 
-        if (PySlice_GetIndicesEx(item,
-                         PyTuple_GET_SIZE(self),
-                         &start, &stop, &step, &slicelength) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelength = PySlice_AdjustIndices(PyTuple_GET_SIZE(self), &start,
+                                            &stop, step);
 
         if (slicelength <= 0) {
             return PyTuple_New(0);
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index b4145719b86..ef2215fbc3c 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -13996,10 +13996,11 @@ unicode_subscript(PyObject* self, PyObject* item)
         int src_kind, dest_kind;
         Py_UCS4 ch, max_char, kind_limit;
 
-        if (PySlice_GetIndicesEx(item, PyUnicode_GET_LENGTH(self),
-                                 &start, &stop, &step, &slicelength) < 0) {
+        if (PySlice_Unpack(item, &start, &stop, &step) < 0) {
             return NULL;
         }
+        slicelength = PySlice_AdjustIndices(PyUnicode_GET_LENGTH(self),
+                                            &start, &stop, step);
 
         if (slicelength <= 0) {
             _Py_RETURN_UNICODE_EMPTY();