diff --git a/package.json b/package.json
index 2da327eebe..f7462a0f3e 100644
--- a/package.json
+++ b/package.json
@@ -50,7 +50,7 @@
     "seed:serve": "UNLEASH_DATABASE_NAME=unleash_test UNLEASH_DATABASE_SCHEMA=seed yarn run start:dev",
     "clean": "del-cli --force dist",
     "preversion": "./scripts/check-release.sh",
-    "heroku-postbuild": "cd frontend && yarn build"
+    "heroku-postbuild": "cd frontend && yarn && yarn build"
   },
   "jest": {
     "automock": false,