diff --git a/Objects/classobject.c b/Objects/classobject.c
index 5362fbc..5500ed5 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -141,7 +141,7 @@
 
 	if (!_PyArg_NoKeywords("instancemethod", kw))
 		return NULL;
-	if (!PyArg_UnpackTuple(args, "method", 2, 3,
+	if (!PyArg_UnpackTuple(args, "method", 2, 2,
 			      &func, &self))
 		return NULL;
 	if (!PyCallable_Check(func)) {