diff --git a/plugins/python/uwsgi_pymodule.c b/plugins/python/uwsgi_pymodule.c
index f15f7ab3..e633d53d 100644
--- a/plugins/python/uwsgi_pymodule.c
+++ b/plugins/python/uwsgi_pymodule.c
@@ -955,7 +955,8 @@ PyObject *py_uwsgi_is_locked(PyObject * self, PyObject * args) {
 
         if (uwsgi_lock_check(uwsgi.user_lock[lock_num]) == 0) {
 		UWSGI_GET_GIL
-		return PyErr_Format(PyExc_Exception, "already locked");
+		Py_INCREF(Py_False);
+		return Py_False;
 	}
 
 	UWSGI_GET_GIL