diff --git a/app.json b/app.json
index dbcdfac7..b8e91752 100644
--- a/app.json
+++ b/app.json
@@ -11,6 +11,7 @@
     "folder",
     "orthodox"
   ],
+  "stack": "heroku-18",
   "env": {
       "NPM_CONFIG_PRODUCTION": {
           "description": "Keep false to install devDependencies and build frontend",