diff --git a/src/EventSubscriber/DefaultSubscriber.php b/src/EventSubscriber/DefaultSubscriber.php
index f58c27d9aa1550a851720c1417352679f0f425d1..13964d3e4a0cf7446d7d4dd2767effdefcad20e4 100644
--- a/src/EventSubscriber/DefaultSubscriber.php
+++ b/src/EventSubscriber/DefaultSubscriber.php
@@ -43,7 +43,7 @@ class DefaultSubscriber implements EventSubscriberInterface {
   /**
    * {@inheritdoc}
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     $events['elasticsearch_connector.prepare_index_mapping'] = ['elasticsearchConnectorPrepareIndexMapping'];
     $events['elasticsearch_connector.prepare_index'] = ['elasticsearchConnectorPrepareIndex'];