diff --git a/modules/http_client_manager_example/src/EventSubscriber/HttpClientManagerExampleSubscriber.php b/modules/http_client_manager_example/src/EventSubscriber/HttpClientManagerExampleSubscriber.php
index cd40402..6205453 100644
--- a/modules/http_client_manager_example/src/EventSubscriber/HttpClientManagerExampleSubscriber.php
+++ b/modules/http_client_manager_example/src/EventSubscriber/HttpClientManagerExampleSubscriber.php
@@ -16,7 +16,7 @@ class HttpClientManagerExampleSubscriber implements EventSubscriberInterface {
   /**
    * {@inheritdoc}
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     return [
       HttpClientEvents::HANDLER_STACK => ['onHandlerStack'],
     ];
diff --git a/src/EventSubscriber/HttpClientManagerSubscriber.php b/src/EventSubscriber/HttpClientManagerSubscriber.php
index 3a912a3..c16d610 100644
--- a/src/EventSubscriber/HttpClientManagerSubscriber.php
+++ b/src/EventSubscriber/HttpClientManagerSubscriber.php
@@ -14,7 +14,7 @@ class HttpClientManagerSubscriber implements EventSubscriberInterface {
   /**
    * {@inheritdoc}
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     return [
       HttpClientEvents::CALL_PRE_EXECUTE => ['onDataIntegrityCheck'],
     ];