Attr_accessible problem

In the user.rb file on the video there is already a generated line for attr_accessible with a few variables. When I look at my user.rb file it only shows..

class User < ActiveRecord::Base # Include default devise modules. Others available are: # :confirmable, :lockable, :timeoutable and :omniauthable devise :database_authenticatable, :registerable, :recoverable, :rememberable, :trackable, :validatable

when I add the attr_accessible and the variables and then run the server I get this error.

attr_accessibleis extracted out of Rails into a gem. Please use new recommended protection model for params(strong_parameters) or addprotected_attributes` to your Gemfile to use old one.

What do I need to do to get this to work?

Thank you