diff --git a/src/EventSubscriber/CsvSubscriber.php b/src/EventSubscriber/CsvSubscriber.php
index e1bb763..e0d1cd4 100644
--- a/src/EventSubscriber/CsvSubscriber.php
+++ b/src/EventSubscriber/CsvSubscriber.php
@@ -24,7 +24,7 @@ class CsvSubscriber implements EventSubscriberInterface {
   /**
    * Implements \Symfony\Component\EventDispatcher\EventSubscriberInterface::getSubscribedEvents().
    */
-  public static function getSubscribedEvents() {
+  public static function getSubscribedEvents(): array {
     $events[KernelEvents::REQUEST][] = ['onKernelRequest'];
     return $events;
   }