Rails 3.1: Devise_invitable requires Rails 3.0.0?

When adding devise_invitable to my Gemfile, I get this error when doing bundle install.

$ bundle install
Fetching source index for http://rubygems.org/
Bundler could not find compatible versions for gem "rails":
  In Gemfile:
    devise_invitable (~> 0.4.0) depends on
      rails (~> 3开发者_如何转开发.0.0)

    rails (3.1.0)

In your Gemfile, update devise_invitable to use a newer version (current is 0.5.4) instead of 0.4.0; 0.5.4 supports Rails 3.1.