```ruby
require 'devise/schema'

module Devise
  module Schema
    def cas_authenticatable
      apply_devise_schema :username, String
    end
  end
end```

Work with Devise 1.1 betas
user
```ruby
require 'devise/schema'

module Devise
  module Schema
    def cas_authenticatable
      if respond_to? :apply_devise_schema
        apply_devise_schema :username, String
      else
        apply_schema :username, String
      end
    end
  end
end
```
assistant