diff --git a/Form/EventType.php b/Form/EventType.php
index 5ad2f6414..623004306 100644
--- a/Form/EventType.php
+++ b/Form/EventType.php
@@ -80,8 +80,10 @@ class EventType extends AbstractType
             ->add('center', EntityType::class, array(
                 'class' => Center::class,
                 'choices' => $userReachableCenters,
+                'attr' => array('class' => 'select2 chill-category-link-parent'),
                 'choice_attr' => function (Center $center) {
                     return array(
+                        'class' => ' chill-category-link-parent',
                         'data-link-category' => $center->getId()
                     );
                 },