diff --git a/synapse/events/utils.py b/synapse/events/utils.py
index b36eec099..48548f8c4 100644
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -66,7 +66,6 @@ def prune_event(event):
             "users_default",
             "events",
             "events_default",
-            "events_default",
             "state_default",
             "ban",
             "kick",