diff --git a/lib/diaspora_federation/schemas/federation_entities.json b/lib/diaspora_federation/schemas/federation_entities.json
index b30af83..4331d58 100644
--- a/lib/diaspora_federation/schemas/federation_entities.json
+++ b/lib/diaspora_federation/schemas/federation_entities.json
@@ -101,7 +101,7 @@
                 "positive": { "type": "boolean" },
                 "parent_type": { "enum": ["Post", "Comment"] }
               },
-              "required": ["positive"]
+              "required": ["positive", "parent_type"]
             }
           }
         }