diff --git a/config/packages/surfnet_stepup.yml b/config/packages/surfnet_stepup.yaml
similarity index 100%
rename from config/packages/surfnet_stepup.yml
rename to config/packages/surfnet_stepup.yaml
diff --git a/src/Kernel.php b/src/Kernel.php
index 3092cc44..e05d2105 100644
--- a/src/Kernel.php
+++ b/src/Kernel.php
@@ -21,52 +21,17 @@
 namespace Surfnet\Webauthn;
 
 use Symfony\Bundle\FrameworkBundle\Kernel\MicroKernelTrait;
-use Symfony\Component\Config\Loader\LoaderInterface;
-use Symfony\Component\Config\Resource\FileResource;
-use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\HttpKernel\Kernel as BaseKernel;
-use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator;
 
 class Kernel extends BaseKernel
 {
     use MicroKernelTrait;
 
-    private const CONFIG_EXTS = '.{php,xml,yaml,yml}';
-
-    public function registerBundles(): iterable
-    {
-        $contents = require $this->getProjectDir().'/config/bundles.php';
-        foreach ($contents as $class => $envs) {
-            if ($envs[$this->environment] ?? $envs['all'] ?? false) {
-                yield new $class();
-            }
-        }
-    }
-
+    /**
+     * see https://symfony.com/doc/current/reference/configuration/kernel.html#kernel-project-dir
+     */
     public function getProjectDir(): string
     {
         return dirname(__DIR__);
     }
-
-    protected function configureContainer(ContainerBuilder $container, LoaderInterface $loader): void
-    {
-        $container->addResource(new FileResource($this->getProjectDir().'/config/bundles.php'));
-        $container->setParameter('.container.dumper.inline_class_loader', PHP_VERSION_ID < 70400 || $this->debug);
-        $container->setParameter('.container.dumper.inline_factories', true);
-        $confDir = $this->getProjectDir().'/config';
-
-        $loader->load($confDir.'/{packages}/*'.self::CONFIG_EXTS, 'glob');
-        $loader->load($confDir.'/{packages}/'.$this->environment.'/**/*'.self::CONFIG_EXTS, 'glob');
-        $loader->load($confDir.'/{services}'.self::CONFIG_EXTS, 'glob');
-        $loader->load($confDir.'/{services}_'.$this->environment.self::CONFIG_EXTS, 'glob');
-    }
-
-    protected function configureRoutes(RoutingConfigurator $routes): void
-    {
-        $confDir = $this->getProjectDir().'/config';
-
-        $routes->import($confDir.'/{routes}/'.$this->environment.'/**/*'.self::CONFIG_EXTS, 'glob');
-        $routes->import($confDir.'/{routes}/*'.self::CONFIG_EXTS, 'glob');
-        $routes->import($confDir.'/{routes}'.self::CONFIG_EXTS, 'glob');
-    }
 }