diff --git a/senlin/engine/scheduler.py b/senlin/engine/scheduler.py
index 4be38356f..d7a39d43c 100644
--- a/senlin/engine/scheduler.py
+++ b/senlin/engine/scheduler.py
@@ -158,7 +158,7 @@ class ThreadGroupManager(object):
         The task will be executed in a separate green thread.
         Interval is from cfg.CONF.periodic_interval
         """
-        timer = self.group.add_timer(interval, func, *args, **kwargs)
+        timer = self.group.add_timer(interval, func, None, *args, **kwargs)
         return timer
 
     def stop_timers(self):
diff --git a/senlin/tests/unit/engine/test_scheduler.py b/senlin/tests/unit/engine/test_scheduler.py
index 0826ac936..2834e4909 100644
--- a/senlin/tests/unit/engine/test_scheduler.py
+++ b/senlin/tests/unit/engine/test_scheduler.py
@@ -70,7 +70,8 @@ class SchedulerTest(base.SenlinTestCase):
         tgm = scheduler.ThreadGroupManager()
         mock_group.add_timer.assert_called_once_with(
             cfg.CONF.periodic_interval,
-            tgm._service_task)
+            tgm._service_task,
+            None)
 
     def test_start(self):
         def f():