diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index c0ff499..52f20f4 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -522,8 +522,8 @@
     PyObject *v;
 
     if (!PyArg_ParseTuple(args, "O|O&O&:index", &v,
-                                _PyEval_SliceIndex, &start,
-                                _PyEval_SliceIndex, &stop))
+                                _PyEval_SliceIndexNotNone, &start,
+                                _PyEval_SliceIndexNotNone, &stop))
         return NULL;
     if (start < 0) {
         start += Py_SIZE(self);