diff --git a/Gemfile b/Gemfile
index eb84edd147..a60c1010d9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -16,6 +16,7 @@ gem "rack",          "1.0.1"
 gem "rack-mount",    :git => "git://github.com/rails/rack-mount.git"
 gem "rack-test",     "~> 0.5.0"
 gem "erubis",        "~> 2.6.0"
+gem "arel", "0.1.3", :git => "git://github.com/rails/arel.git"
 gem "mocha"
 gem "sqlite3-ruby"
 gem "RedCloth"