diff --git a/specification/cosmos-db/resource-manager/Microsoft.DocumentDB/preview/2021-04-01-preview/services.json b/specification/cosmos-db/resource-manager/Microsoft.DocumentDB/preview/2021-04-01-preview/services.json
index 8e2193e8d839..61d4fd8933c8 100644
--- a/specification/cosmos-db/resource-manager/Microsoft.DocumentDB/preview/2021-04-01-preview/services.json
+++ b/specification/cosmos-db/resource-manager/Microsoft.DocumentDB/preview/2021-04-01-preview/services.json
@@ -282,6 +282,9 @@
         "properties": {
           "x-ms-client-flatten": true,
           "$ref": "#/definitions/ServiceResourceProperties"
+        },
+        "additionalProperties": {
+          "type": "object"
         }
       }
     },