diff --git a/etc/export.schema.json b/etc/export.schema.json
index 3bb7bc6d5..684f4d498 100644
--- a/etc/export.schema.json
+++ b/etc/export.schema.json
@@ -366,7 +366,7 @@
                     "type": "string"
                   },
                   "with_gene_id": {
-                    "type": "string"
+                    "$ref": "#/definitions/nullableString"
                   }
                 },
                 "required": [