diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index 145f8b070..7dbf38e87 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -71,6 +71,7 @@ npm test
 Creating a release means compiling all the TypeScript code to a single file which `setup-php` can run. Run this, before you push your changes.
 
 ```bash
+npm run build
 npm run release
 ```