diff --git a/Python/ceval.c b/Python/ceval.c
index 978ff61..1f18545 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -3900,7 +3900,7 @@
 {
 	if (v != NULL) {
 		Py_ssize_t x;
-		if (PyInt_Check(v)) {
+		if (PyInt_CheckExact(v)) {
 			/* XXX(nnorwitz): I think PyInt_AS_LONG is correct,
 			   however, it looks like it should be AsSsize_t.
 			   There should be a comment here explaining why.