diff --git a/x-pack/plugin/src/test/resources/rest-api-spec/api/data_frame.preview_data_frame_transform.json b/x-pack/plugin/src/test/resources/rest-api-spec/api/data_frame.preview_data_frame_transform.json
index e5e9b1be949..c8cf76e90d3 100644
--- a/x-pack/plugin/src/test/resources/rest-api-spec/api/data_frame.preview_data_frame_transform.json
+++ b/x-pack/plugin/src/test/resources/rest-api-spec/api/data_frame.preview_data_frame_transform.json
@@ -1,6 +1,6 @@
 {
   "data_frame.preview_data_frame_transform": {
-    "documentation": "TODO",
+    "documentation": "https://www.elastic.co/guide/en/elasticsearch/reference/current/preview-data-frame-transform.html",
     "methods": [ "POST" ],
     "url": {
       "path": "/_data_frame/transforms/_preview",