diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 390b670..72b79c9 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -689,7 +689,7 @@
         PyObject* it;
         PyObject **src, **dest;
 
-        if (PySlice_GetIndicesEx((PySliceObject*)item,
+        if (PySlice_GetIndicesEx(item,
                          PyTuple_GET_SIZE(self),
                          &start, &stop, &step, &slicelength) < 0) {
             return NULL;