diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index bd8af72..03cd7dd 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -3,6 +3,7 @@
 #define PY_SSIZE_T_CLEAN
 
 #include "Python.h"
+#include "pycore_abstract.h"   // _PyIndex_Check()
 #include "pycore_bytes_methods.h"
 #include "pycore_object.h"
 #include "pycore_pymem.h"
@@ -1579,7 +1580,7 @@
 static PyObject*
 bytes_subscript(PyBytesObject* self, PyObject* item)
 {
-    if (PyIndex_Check(item)) {
+    if (_PyIndex_Check(item)) {
         Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);
         if (i == -1 && PyErr_Occurred())
             return NULL;
@@ -2536,7 +2537,7 @@
         return NULL;
     }
     /* Is it an integer? */
-    if (PyIndex_Check(x)) {
+    if (_PyIndex_Check(x)) {
         size = PyNumber_AsSsize_t(x, PyExc_OverflowError);
         if (size == -1 && PyErr_Occurred()) {
             if (!PyErr_ExceptionMatches(PyExc_TypeError))