diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 0161fbe49c..322c1b407d 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -716,6 +716,8 @@ class FederationHandler(BaseHandler):
 
             context.rejected = RejectedReason.AUTH_ERROR
 
+            # FIXME: Don't store as rejected with AUTH_ERROR if we haven't
+            # seen all the auth events.
             yield self.store.persist_event(
                 event,
                 context=context,