diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index 3a073b6..83dacfd5 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -88,7 +88,7 @@
 	int setup_op = 0;               /* (ditto) */
 
 	/* f_lineno must be an integer. */
-	if (!PyInt_Check(p_new_lineno)) {
+	if (!PyInt_CheckExact(p_new_lineno)) {
 		PyErr_SetString(PyExc_ValueError,
 				"lineno must be an integer");
 		return -1;