diff --git a/src/DependencyInjection/ExerciseHTMLPurifierExtension.php b/src/DependencyInjection/ExerciseHTMLPurifierExtension.php
index 861feca3..8dd3fa37 100644
--- a/src/DependencyInjection/ExerciseHTMLPurifierExtension.php
+++ b/src/DependencyInjection/ExerciseHTMLPurifierExtension.php
@@ -10,7 +10,7 @@
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
 use Symfony\Component\DependencyInjection\Reference;
-use Symfony\Component\HttpKernel\DependencyInjection\Extension;
+use Symfony\Component\DependencyInjection\Extension\Extension;
 
 class ExerciseHTMLPurifierExtension extends Extension
 {