Merge branches/pep-0384.
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 13d7f55..8a22752 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -762,7 +762,7 @@
     else if (PySlice_Check(item)) {
         Py_ssize_t start, stop, step, slicelen;
 
-        if (PySlice_GetIndicesEx((PySliceObject *)item, self->size,
+        if (PySlice_GetIndicesEx(item, self->size,
                          &start, &stop, &step, &slicelen) < 0) {
             return NULL;
         }
@@ -888,7 +888,7 @@
         Py_ssize_t start, stop, step, slicelen;
         Py_buffer vbuf;
 
-        if (PySlice_GetIndicesEx((PySliceObject *)item,
+        if (PySlice_GetIndicesEx(item,
                                  self->size, &start, &stop,
                                  &step, &slicelen) < 0) {
             return -1;