diff --git a/Gemfile b/Gemfile
index f449053..996651e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'http://rubygems.org'
 
-gem 'rails', '3.1.1'
+gem 'rails', '4.0.0'
 
 # Bundle edge Rails instead:
 # gem 'rails',     :git => 'git://github.com/rails/rails.git'