1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/handlers/devicemessage.py b/synapse/handlers/devicemessage.py
index fc974a82e8..0c7737e09d 100644
--- a/synapse/handlers/devicemessage.py
+++ b/synapse/handlers/devicemessage.py
@@ -163,7 +163,7 @@ class DeviceMessageHandler:
             await self.store.mark_remote_user_device_cache_as_stale(sender_user_id)
 
             # Immediately attempt a resync in the background
-            run_in_background(self._user_device_resync, sender_user_id)
+            run_in_background(self._user_device_resync, user_id=sender_user_id)
 
     async def send_device_message(
         self,