store.filter() doesn't work in route

I would like to use the live-update capabilities of store.filter(). That's why I would like to use it in a route.

This doesn't work:

import Ember from 'ember';

export default Ember.Route.extend({
   model: function() {
      return this.store.filter('post', function () { return true; })
  }
});

This works:

import Ember from 'ember';

export default Ember.Route.extend({
   model: function() {
      return this.store.find('post', { sort:'createdAt desc'});
  }
});