Normalizing specific model payload on Ember 2.0

I'm trying to request a JSON structure that is not common for the Ember default adapter. The response does not have the root key. Here's what I mean:

[
  {
    name: 'Dude'
    fullName: 'Nice Dude'
  },
  { 
    name: 'Foo'
    fullName: 'Foo Bar'
  }
]

So, let's say that this is the response for GET /users.

I can workaround and successfully resolve this writing this boilerplate:

import DS from 'ember-data';

export default DS.RESTSerializer.extend({
  normalizePayload: function(payload) {
    return { user: payload };
  }
});

But this is totally wrong, cause i'm overwriting all payload responses. Which would be the clean way of normalizing only GET /users payload?