diff --git a/f7/app.py b/f7/app.py
index 5fe05f7..3c7d7a1 100644
--- a/f7/app.py
+++ b/f7/app.py
@@ -26,6 +26,7 @@ class _App:
         return cls._instance
 
     def __init__(self):
+        self.ext = {}
         self._listened = False
         self._requestHandler = {}
         self._app = tornado.web.Application([