diff --git a/lib/schemas/api_v1.json b/lib/schemas/api_v1.json
index a8c383417..84511bd4a 100644
--- a/lib/schemas/api_v1.json
+++ b/lib/schemas/api_v1.json
@@ -211,7 +211,7 @@
         "small": { "$ref": "https://diaspora.software/api/v1/schema.json#/definitions/url" }
       },
       "required": ["raw", "large", "medium", "small"],
-      "additionalProperties": true
+      "additionalProperties": false
     },
 
     "photo_dimensions": {