diff --git a/synapse/handlers/directory.py b/synapse/handlers/directory.py
index a1e1cd1c3..f3b3dbd34 100644
--- a/synapse/handlers/directory.py
+++ b/synapse/handlers/directory.py
@@ -117,7 +117,10 @@ class DirectoryHandler:
         user_id = requester.user.to_string()
         room_alias_str = room_alias.to_string()
 
-        if len(room_alias_str) > MAX_ALIAS_LENGTH:
+        if (
+            user_id not in self.hs.config.meow.validation_override
+            and len(room_alias_str) > MAX_ALIAS_LENGTH
+        ):
             raise SynapseError(
                 400,
                 "Can't create aliases longer than %s characters" % MAX_ALIAS_LENGTH,