EmberJS registerHelper to dynamically render a template in Ember 1.8

I'd like to dynamically render a template, like this:

{{#each layout in layouts}}
   {{render layout.get('type') layout}}
{{/each}} 

The problem is that render doesn't expect a variable as its first arguments, so in the older EmberJS-versions, a workaround was possible by registering a helper:

Ember.Handlebars.registerBoundHelper('render_layout', 
  function(callingContext, layout, options) {
    return Ember.Handlebars.helpers.render.call(callingContext, 
                layout.get('type'), 'layout', options);
});

and in the template:

{{#each layout in layouts}}
     {{render_layout this layout}}
{{/each}} 

Unfortunately the thing doesn't work in newer ember versions. Ember.Handlebars.helpers.render.call expects 3 arguments but I can not get them right. Any ideas? I've tried: (this, layout.get('type'), options)

and in the template:

{{#each layout in layouts}}
     {{render_layout layout}}
{{/each}} 

... and many others.

Any suggestions would be greatly appreciated.