Unknown provider: angularFireAuthProvider

I’m trying to use the firebase auth provider similar to this tutorial. I’m getting the following error and I’m not sure how to triage it.

Uncaught Error: [$injector:unpr] Unknown provider: angularFireAuthProvider <- angularFireAuth

My app.js looks like this:

'use strict';
var app = angular.module('wefeed',
          , 'wefeed.config'
          , 'wefeed.controllers.signin'
          , 'wefeed.controllers.signup'
          , 'firebase']);

and my config.js:

'use strict';

// Declare app level module which depends on filters, and services
angular.module('wefeed.config', [])

    function($stateProvider) {
      .state('default', {
          url: '/',
          templateUrl: 'views/default.html' })

      //.state('/',                    { templateUrl: 'views/default.html' })
      .state('signin', {
        url: '/signin',
         templateUrl: 'views/users/signin.html' })

      .state('signup', {
       url: '/signup',
        templateUrl: 'views/users/signup.html' })
      //.when('/signup',              { templateUrl: 'views/users/signup.html' })
      //.when('/nflteams',            { templateUrl: 'views/nfl/list.html'
      //                              , authRequired: true })
      //.otherwise(                   { redirectTo: '/' });

  // establish authentication
  .run(['angularFireAuth', 'FBURL', '$rootScope',
    function(angularFireAuth, FBURL, $rootScope) {
      angularFireAuth.initialize(new Firebase(FBURL), {scope: $rootScope, name: 'auth', path: '/signin'});
      $rootScope.FBURL = FBURL;

  // your Firebase URL goes here
  // should look something like: https://blahblahblah.firebaseio.com
  .constant('FBURL', 'https://blahblahblah.firebaseio.com')

I’m happy to provide other code too, I’m not sure what is going on here.