diff --git a/docker/complement/conf/workers-shared-extra.yaml.j2 b/docker/complement/conf/workers-shared-extra.yaml.j2
index 32eada44197..56cdc16094e 100644
--- a/docker/complement/conf/workers-shared-extra.yaml.j2
+++ b/docker/complement/conf/workers-shared-extra.yaml.j2
@@ -104,6 +104,8 @@ experimental_features:
   msc3874_enabled: true
   # no UIA for x-signing upload for the first time
   msc3967_enabled: true
+  # Expose a room summary for public rooms
+  msc3266_enabled: true
 
 server_notices:
   system_mxid_localpart: _server