Let''s say I have a plugin for for ActionController. I only want the plugin loaded if ActionController is loaded. Rails has put a lot of effort into autoloading only the necessary files during startup. Is there a good way for the ActionController plugin to load only when the ActionController module is loaded? For example, most plugins would do the following: ActionController.class_eval do include UberControllerPlugin end The above lines cause all of ActionController to be loaded for all tests and server startups. Is there a way to "autoload" the plugin only after the ActionController module has been referenced?