Routes within different, smaller files not recognized

When having a config/routes.rb file like this:

Rails.application.routes.draw do
  extend ApiRoutes
  extend UserRoutes
  extend AdminRoutes
  # ... many more routes
end

A smaller route file looks like this:

module UserRoutes
  def self.extended(router)
    router.instance_exec do
      namespace :user do
        resources :something
        # .. etc.
      end
    end
  end
end

RubyMine complains that it can't find the paths. Is there a way to configure RubyMine to find it? 

Note: This is a Rails 4 application and application.rb loads routes modules like this:

config.autoload_paths += %W(#{config.root}/config/routes)

EDIT: Looks like it detects some routes, but not others, this definitely looks like an issue.