diff --git a/free-programming-books.md b/free-programming-books.md
index ce3d852e19c282bd34f3fe8459eba7e8d059b54c..bf42a41fd3f474882ae06a51f05410a5d4aa45b5 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -873,6 +873,7 @@ See also [TeX](#tex)
 * [Objects on Rails](http://objectsonrails.com)
 * [Ruby on Rails Guides](http://guides.rubyonrails.org)
 * [A community-driven Rails style guide](https://github.com/bbatsov/rails-style-guide)
+* [Upgrading to Rails 4](https://github.com/alindeman/upgradingtorails4)
 
 
 ###Rust