diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index f4461c05530..572b5d1c08d 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -4616,7 +4616,7 @@ static PyObject *
 sched_param_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 {
     PyObject *res, *priority;
-    static char *kwlist[] = {"sched_priority"};
+    static char *kwlist[] = {"sched_priority", NULL};
 
     if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O:sched_param", kwlist, &priority))
         return NULL;