diff --git a/app.json b/app.json
index b4c3d43..7ca7f21 100644
--- a/app.json
+++ b/app.json
@@ -20,5 +20,6 @@
     {
       "url": "heroku/nodejs"
     }
-  ]
+  ],
+  "stack": "heroku-22"
 }