diff --git a/telethon/network/mtprotosender.py b/telethon/network/mtprotosender.py
index 7f9c8c82..5464f48c 100644
--- a/telethon/network/mtprotosender.py
+++ b/telethon/network/mtprotosender.py
@@ -122,6 +122,7 @@ class MTProtoSender:
         await self._connect()
         self._user_connected = True
 
+    @property
     def is_connected(self):
         return self._user_connected