Using Gemfiles on Rails 2.x apps February 14, 2011 If your Rails 2.X applications stored its gem configuration in the config/environment.rb file and you want to begin using Gemfiles then you need to follow a few simple rules #if the line reads like this: $ gem "authlogic", :version => '>=2.1.3' #then in your Gemfile you should put $ gem "authlogic", '>=2.1.3' #if it reads like this $ gem 'activerecord-tableless', :lib => 'tableless', :version => '0.1.0' #then the corresponding Gemfile entry should go like: $ gem 'activerecord-tableless', '0.1.0', :require => 'tableless' Easy isnt? Now you only need one more thing $ bundle install and you are ready to go