diff --git a/api/core/moderation/base.py b/api/core/moderation/base.py
index d76b4689be..31dd0d5568 100644
--- a/api/core/moderation/base.py
+++ b/api/core/moderation/base.py
@@ -39,7 +39,7 @@ class Moderation(Extensible, ABC):
 
     @classmethod
     @abstractmethod
-    def validate_config(cls, tenant_id: str, config: dict):
+    def validate_config(cls, tenant_id: str, config: dict) -> None:
         """
         Validate the incoming form config data.