diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 645480c..7456533 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -753,7 +753,7 @@
 		PyErr_BadInternalCall();
 		return NULL;
 	}
-	if (seq->ob_type->tp_as_sequence->sq_item != tupleitem)
+	if (seq->ob_type->tp_as_sequence->sq_item != (intargfunc)tupleitem)
 		return PySeqIter_New(seq);
 	it = PyObject_GC_New(tupleiterobject, &PyTupleIter_Type);
 	if (it == NULL)