diff --git a/json/resources/jsonSchema/vocabularies/2020-12/validation.json b/json/resources/jsonSchema/vocabularies/2020-12/validation.json
index 5e30322a554e..5234826743cc 100644
--- a/json/resources/jsonSchema/vocabularies/2020-12/validation.json
+++ b/json/resources/jsonSchema/vocabularies/2020-12/validation.json
@@ -75,6 +75,7 @@
       "default": 0
     },
     "simpleTypes": {
+      "type": "string",
       "enum": [
         "array",
         "boolean",