1 files changed, 3 insertions, 0 deletions
diff --git a/synapse/handlers/oidc_handler.py b/synapse/handlers/oidc_handler.py
index c5bd2fea68..1b06f3173f 100644
--- a/synapse/handlers/oidc_handler.py
+++ b/synapse/handlers/oidc_handler.py
@@ -869,6 +869,9 @@ class OidcHandler:
             raise MappingException(
                 "Failed to extract subject from OIDC response: %s" % (e,)
             )
+        # Some OIDC providers use integer IDs, but Synapse expects external IDs
+        # to be strings.
+        remote_user_id = str(remote_user_id)
 
         logger.info(
             "Looking for existing mapping for user %s:%s",