1 files changed, 3 insertions, 1 deletions
diff --git a/synapse/server.py b/synapse/server.py
index 559724594b..08ad97b952 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -762,7 +762,9 @@ class HomeServer(metaclass=abc.ABCMeta):
 
     @cache_in_self
     def get_event_client_serializer(self) -> EventClientSerializer:
-        return EventClientSerializer()
+        return EventClientSerializer(
+            msc3970_enabled=self.config.experimental.msc3970_enabled
+        )
 
     @cache_in_self
     def get_password_policy_handler(self) -> PasswordPolicyHandler: