diff --git a/synapse/appservice/scheduler.py b/synapse/appservice/scheduler.py
index d90d45b643..ac8684407b 100644
--- a/synapse/appservice/scheduler.py
+++ b/synapse/appservice/scheduler.py
@@ -159,6 +159,7 @@ class ApplicationServiceScheduler:
                 event for event in events if not self._hs.is_mine_id(event.sender)
             ]
 
+        if events:
             self.queuer.queued_events.setdefault(appservice.id, []).extend(events)
         if ephemeral:
             self.queuer.queued_ephemeral.setdefault(appservice.id, []).extend(ephemeral)