Devise Invitable With Strong Parameters Gem

Here is a simple way to get things working with strong_parameters:

# config/initializers/devise_invitable_strong_parameters.rb
Devise::InvitationsController.class_eval do
  def resource_params
    params.require(resource_name).permit(
      :invitation_token,
      :password,
      :password_confirmation
    )
  end
end