Ruby: How do you configure an enum in a fixture?

Given this class:

class User < ActiveRecord::Base

enum permission: {
    permission_user: 1,
    permission_staff: 2,
    permission_manager: 3,
    permission_admin: 4,
    permission_super_admin: 5
}

I want to create a fixture that looks like this:

testuser1:
  id: 1
  username: sam
  permission: :permission_staff

I've tried a number of variations of syntax, but haven't found something that works. the resulting user.permission is either nil or 0. I know that enum is relatively recent addition. Can this be done?