Laravel 5.4 Event::fire

I am currenly trying to make a Laravel package from 5.0 compatible with 5.4.

I am stuck with Event::fire

example code

Event::fire('u2f.register.data', ['user' => Auth::user()]);

But the package has file with in it

 /**
 * Bootstrap the application events.
 *
 * @return void
 */
public function boot(Router $router)
{
    $routeConfig = [
        'namespace'  => '\Certly\U2f\Http\Controllers',
        'prefix'     => '/u2f/',
        'middleware' => $this->app[ 'config' ]->get('u2f.authMiddlewareName', 'auth'),
    ];
    $this->app[ 'router' ]->group($routeConfig, function (Router $router) {
        $router->get('register', [
            'uses'       => 'U2fController@registerData',
            'as'         => 'u2f.register.data',
            'middleware' => 'u2f',
        ]);
        $router->post('register', [
            'uses'       => 'U2fController@register',
            'as'         => 'u2f.register',
            'middleware' => 'u2f',
        ]);

How could I make the Event::fire compatible to Laravel 5.4. At first I thought event('u2f.register.data', ['user' => $user]);

But that didn't seem to help.

The package I am talking about https://github.com/certly/laravel-u2f

via Romano