1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index afdb5bf2fa..55533d7501 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -102,7 +102,7 @@ class FederationClient(FederationBase):
             max_len=1000,
             expiry_ms=120 * 1000,
             reset_expiry_on_get=False,
-        )
+        )  # type: ExpiringCache[str, EventBase]
 
     def _clear_tried_cache(self):
         """Clear pdu_destination_tried cache"""