diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index 1de23ff..260e477 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -931,7 +931,7 @@ protected function initializeContainer() {
 
     // Allow other parts of the codebase to react on container initialization in
     // subrequest.
-    if (isset($subrequest) && $subrequest) {
+    if (!empty($subrequest)) {
       $this->container->get('event_dispatcher')->dispatch(self::CONTAINER_INITIALIZE_SUBREQUEST_FINISHED);
     }