diff --git a/f7/app.py b/f7/app.py
index 28238b3..5fe05f7 100644
--- a/f7/app.py
+++ b/f7/app.py
@@ -115,7 +115,10 @@ class _App:
         assert self._listened
         def thread_func(args):
             try:
-                func(args)
+                if len(args) > 0:
+                    func(args)
+                else:
+                    func()
             except Exception as e:
                 f7.udplog.error('_dispatchIMMsg ' + str(e))
             if done_callback: