diff --git a/BUILD.md b/BUILD.md
index efdd7992..ff720771 100644
--- a/BUILD.md
+++ b/BUILD.md
@@ -65,4 +65,4 @@ To add/update a library to the latest version, run `npm install PACKAGE_NAME@lat
 
 To remove a library, run `npm uninstall PACKAGE_NAME`.
 
-After the (un)installation, run `npm run build-vendor` to rebuild the vendor folder.
+After the (un)installation, specify files which should be copied in `tools/build-vendor.js` and run `npm run build-vendor` to rebuild the vendor folder.