1 files changed, 9 insertions, 6 deletions
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index fe92457ba1..2a589524a4 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -193,13 +193,16 @@ class FederationServer(FederationBase):
             )
 
             for event in auth_chain:
-                event.signatures.update(
-                    compute_event_signature(
-                        event,
-                        self.hs.hostname,
-                        self.hs.config.signing_key[0]
+                # We sign these again because there was a bug where we
+                # incorrectly signed things the first time round
+                if self.hs.is_mine_id(event.event_id):
+                    event.signatures.update(
+                        compute_event_signature(
+                            event,
+                            self.hs.hostname,
+                            self.hs.config.signing_key[0]
+                        )
                     )
-                )
         else:
             raise NotImplementedError("Specify an event")