diff --git a/README.md b/README.md
index 6fe367d..d1e89e1 100644
--- a/README.md
+++ b/README.md
@@ -8,4 +8,4 @@ Clone this repositiory.
 
 Run `bundle install` inside the clone directory.
 
-Then run `ruby ./pacman-update-notify.rb`.
+Then run `bundle exec ruby ./pacman-update-notify.rb`.