diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index fd75a1874..aa9ac232f 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -1119,7 +1119,7 @@ class EventCreationHandler:
 
         await self.base_handler.maybe_kick_guest_users(event, context)
 
-        validation_override = event.sender not in self.config.meow.validation_override
+        validation_override = event.sender in self.config.meow.validation_override
         if event.type == EventTypes.CanonicalAlias and not validation_override:
             # Validate a newly added alias or newly added alt_aliases.