1 files changed, 4 insertions, 0 deletions
diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py
index 8dbf9bef3f..4eb0036edd 100644
--- a/synapse/handlers/identity.py
+++ b/synapse/handlers/identity.py
@@ -555,6 +555,10 @@ class IdentityHandler(BaseHandler):
         except RequestTimedOutError:
             raise SynapseError(500, "Timed out contacting identity server")
 
+        # It is already checked that public_baseurl is configured since this code
+        # should only be used if account_threepid_delegate_msisdn is true.
+        assert self.hs.config.public_baseurl
+
         # we need to tell the client to send the token back to us, since it doesn't
         # otherwise know where to send it, so add submit_url response parameter
         # (see also MSC2078)