diff --git a/src/EventSubscriber/ConfigImportSubscriber.php b/src/EventSubscriber/ConfigImportSubscriber.php
index 85f4060..cb8a44b 100644
--- a/src/EventSubscriber/ConfigImportSubscriber.php
+++ b/src/EventSubscriber/ConfigImportSubscriber.php
@@ -33,7 +33,7 @@ class ConfigImportSubscriber implements EventSubscriberInterface {
   /**
    * {@inheritdoc}
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     return [
       ConfigEvents::STORAGE_TRANSFORM_IMPORT => ['onImportTransform'],
       // There is no specific reason for choosing 50 beside it should be