1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/events/utils.py b/synapse/events/utils.py
index f86113a448..38fccd1efc 100644
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -105,7 +105,7 @@ def prune_event_dict(room_version: RoomVersion, event_dict: dict) -> dict:
     if event_type == EventTypes.Member:
         add_fields("membership")
         if room_version.msc3375_redaction_rules:
-            add_fields("join_authorised_via_users_server")
+            add_fields(EventContentFields.AUTHORISING_USER)
     elif event_type == EventTypes.Create:
         # MSC2176 rules state that create events cannot be redacted.
         if room_version.msc2176_redaction_rules: