Authentication state ember-simple-auth

I am using this configuration pattern in ESA, which was working up to Ember 2.9.2:

//config/environment.js
'ember-simple-auth': {
  authenticationRoute: 'visitor.login',
  routeAfterAuthentication: 'app',
  routeIfAlreadyAuthenticated: 'app'
}


//app/router.js
Router.map(function() {
  // This route is the only one with the `UnauthenticatedRouteMixin`
  this.route('visitor', { path: '' }, function() {
    this.route('login');
  });
  // This route is the only one with the `AuthenticatedRouteMixin`
  this.route('app', { path: '/' }, function() {
    this.route('my_account');
  });
});

This used to work very well up to Ember 2.9.2, but when moving to Ember 2.10, I ended up with an Error You may not add a duplicate route named 'application'.

Is the configuration pattern above a bad practice? How could I work around it?

Thanks for your help!