diff --git a/telethon/network/mtprotosender.py b/telethon/network/mtprotosender.py
index 6239ffc1..a42dc685 100644
--- a/telethon/network/mtprotosender.py
+++ b/telethon/network/mtprotosender.py
@@ -571,7 +571,7 @@ class MTProtoSender:
         __log__.debug('Handling update {}'
                       .format(message.obj.__class__.__name__))
         if self._update_callback:
-           await self._update_callback(message.obj)
+            self._update_callback(message.obj)
 
     async def _handle_pong(self, message):
         """