diff --git a/src/EventSubscriber/BlockPageDisplayVariantSubscriber.php b/src/EventSubscriber/BlockPageDisplayVariantSubscriber.php
index e0fa693..240e964 100644
--- a/src/EventSubscriber/BlockPageDisplayVariantSubscriber.php
+++ b/src/EventSubscriber/BlockPageDisplayVariantSubscriber.php
@@ -52,7 +52,7 @@ class BlockPageDisplayVariantSubscriber implements EventSubscriberInterface {
   /**
    * {@inheritdoc}
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     $events[RenderEvents::SELECT_PAGE_DISPLAY_VARIANT][] = ['onSelectPageDisplayVariant'];
     return $events;
   }