Unable to import file from ember-cli generated utils folder

I have generated a utility using ember generate util and I'm trying to import it in another file, but I get a build error.

My utility (app/utils/swapi-adapter.js):

import Ember from 'ember';

/* global $ */
export default Ember.Object.extend({
  base: 'http://swapi.co/api/',

  get: function(uri) {
    var url = uri;

    // make sure to append url
    if(url.indexOf(this.get('base')) !== -1) {
       url = this.get('base') + url;
    }

    return $.getJSON(url);
  }
});

The route I'm trying to import it to: (app/routes/test-api.js)

import Ember from 'ember';
import SWAPI from 'utils/swapi-adapter';

export default Ember.Route.extend({
  model: {},
  actions: {
    test: function(url) {
      SWAPI.get(url);
    }
  }
});