<?php

namespace Palmtree\CanonicalUrlBundle\DependencyInjection;

use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Extension\Extension;
use Symfony\Component\DependencyInjection\Loader;

class PalmtreeCanonicalUrlExtension extends Extension
{
    /**
     * {@inheritdoc}
     */
    public function load(array $configs, ContainerBuilder $container)
    {
        $configuration = new Configuration();
        $config        = $this->processConfiguration($configuration, $configs);

        $container->setParameter('palmtree.canonical_url.site_url', $config['site_url']);
        $container->setParameter('palmtree.canonical_url.redirect_code', $config['redirect_code']);

        $loader = new Loader\YamlFileLoader($container, new FileLocator(__DIR__ . '/../Resources/config'));
        $loader->load('services.yml');
    }
}

<?php

namespace Palmtree\CanonicalUrlBundle\DependencyInjection;

use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;

/**
 * This is the class that loads and manages your bundle configuration.
 *
 * @link http://symfony.com/doc/current/cookbook/bundles/extension.html
 */
class PalmtreeCanonicalUrlExtension extends Extension
{
    /**
     * {@inheritdoc}
     */
    public function load(array $configs, ContainerBuilder $container)
    {
        $configuration = new Configuration();
        $config        = $this->processConfiguration($configuration, $configs);

        $container->setParameter('palmtree.canonical_url.site_url', $config['site_url']);
        $container->setParameter('palmtree.canonical_url.redirect_code', $config['redirect_code']);

        $loader = new Loader\YamlFileLoader($container, new FileLocator(__DIR__ . '/../Resources/config'));
        $loader->load('services.yml');
    }
}

--- 
+++ 
@@ -4,14 +4,9 @@
 
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Extension\Extension;
 use Symfony\Component\DependencyInjection\Loader;
-use Symfony\Component\HttpKernel\DependencyInjection\Extension;
 
-/**
- * This is the class that loads and manages your bundle configuration.
- *
- * @link http://symfony.com/doc/current/cookbook/bundles/extension.html
- */
 class PalmtreeCanonicalUrlExtension extends Extension
 {
     /**
Use DI Extension instead of HttpKernel
