diff --git a/Python/ceval.c b/Python/ceval.c
index 70086e1..b4efa33 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -2708,7 +2708,7 @@
 		Py_UNICODE *cellname, *argname;
 		PyObject *c;
 
-		nargs = co->co_argcount;
+		nargs = co->co_argcount + co->co_kwonlyargcount;
 		if (co->co_flags & CO_VARARGS)
 			nargs++;
 		if (co->co_flags & CO_VARKEYWORDS)