diff --git a/schema/contentobject.schema.json b/schema/contentobject.schema.json
index 9a55788e..6f81cc93 100644
--- a/schema/contentobject.schema.json
+++ b/schema/contentobject.schema.json
@@ -52,7 +52,6 @@
             },
             "src": {
               "type": "string",
-              "isObjectId": true,
               "title": "Source",
               "_backboneForms": {
                 "type": "Asset",
diff --git a/schema/course.schema.json b/schema/course.schema.json
index 8eba32b1..edd03630 100644
--- a/schema/course.schema.json
+++ b/schema/course.schema.json
@@ -13,7 +13,6 @@
         },
         "heroImage": {
           "type": "string",
-          "isObjectId": true,
           "title": "Preview image",
           "description": "The image that will be shown in the dashboard for this course",
           "_adapt": {