Different Bus Provider not working

Hi,

Trying to use a different Bus provider for my application by doing the following:

bootstrap/app.php

<?php
// ...
/*
|--------------------------------------------------------------------------
| Register Service Providers
|--------------------------------------------------------------------------
|
| Here we will register all of the application's service providers which
| are used to bind services into the container. Service providers are
| totally optional, so you are not required to uncomment this line.
|
*/
$app->register(App\Providers\AppServiceProvider::class);
$app->register(App\Providers\BusServiceProvider::class);

app/Providers/BusServiceProvider.php

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;

class BusServiceProvider extends ServiceProvider
{
    /**
     * Register the service provider.
     *
     * @return void
     */
    public function register()
    {
        $this->app->bind('Illuminate\Contracts\Bus\Dispatcher', function ($app) {
            return new \AltThree\Bus\Dispatcher($app);
        });
    }
}

But whenever I inject Illuminate\Contracts\Bus\Dispatcher, I get an instance of Illuminate\Bus\Dispatcher which obviously isn't the right one.

Does anyone know where I'm going wrong?

Thanks!