diff --git a/f7/app.py b/f7/app.py
index 06dafa7..9c8d238 100644
--- a/f7/app.py
+++ b/f7/app.py
@@ -34,7 +34,7 @@ class _App:
         self.registerHandler('Ops', 'selfChecking', self.__selfChecking)
         self._immsgLock = threading.Lock()
         self._immsgList = []
-        tornado.ioloop.IOLoop.PeriodicCallback(self._processIMMsg, 100)
+        tornado.ioloop.PeriodicCallback(self._processIMMsg, 100).start()
 
     def init(self, log_dir):
         f7.udplog.init()