diff --git a/readme.md b/readme.md
index 89b60de..b3d639a 100644
--- a/readme.md
+++ b/readme.md
@@ -50,5 +50,5 @@ $ heroku plugins:link .
 
 ### Add-ons
 
-The mapping from Heroku add-on specified in `app.json` to container configured in `docker-composer.yml` is tracked in `lib\app.json`.
+The mapping from Heroku add-on specified in `app.json` to container configured in `docker-composer.yml` is tracked in `lib\addons.js`.
 The mapping currently includes a limited subset of add-ons that we have tested. We welcome additions in the form of PRs.