adding second model to route makes first undefined

In my current Ember setup, I retrieve a store for the Index Route. This works fine.

 App.IndexRoute = Ember.Route.extend({

    model: function(){      
          var store = this.store.find('index');        
          return store;
        }

  });

However, I wish to create a custom form object for the same route, and therefore following the advice of this SO answertried to return two models for the Index Route like this, however, I now get the error

Error while processing route: index that is not defined ReferenceError: that is not defined

New Code

  App.IndexRoute = Ember.Route.extend({

    model: function(){      

          return Ember.RSVP.hash({
           store: this.store.find('index'),
           customform: App.CustomForm.create()
          });
       }


  });

How can I add a second model to this route?