1 files changed, 1 insertions, 0 deletions
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index f49e8a2cc4..cc9bc7f14b 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -163,6 +163,7 @@ class TransportLayerClient(object):
             data=json_data,
             json_data_callback=json_data_callback,
             long_retries=True,
+            backoff_on_404=True,  # If we get a 404 the other side has gone
         )
 
         logger.debug(