diff --git a/scripts/upgrade b/scripts/upgrade
index 2080e5a..d57e5e2 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -133,7 +133,7 @@ chown -R "$app":"$app" "$final_path"
 
 pushd $final_path
     ynh_use_nodejs
-    sudo -u $app env PATH=$PATH:$nodejs_path npm install
+    sudo -u $app env PATH=$PATH:$nodejs_path yarn install
     sudo -u $app env PATH=$PATH:$nodejs_path npm run build
 popd