diff -u b/core/lib/Drupal/Core/Database/ReplicaKillSwitchRequest.php b/core/lib/Drupal/Core/Database/ReplicaKillSwitchRequest.php
--- b/core/lib/Drupal/Core/Database/ReplicaKillSwitchRequest.php
+++ b/core/lib/Drupal/Core/Database/ReplicaKillSwitchRequest.php
@@ -13,7 +13,8 @@
 class ReplicaKillSwitchRequest implements ReplicaKillSwitchInterface, EventSubscriberInterface {
 
   /**
-   * @var \Drupal\Core\Http\RequestStack */
+   * @var \Drupal\Core\Http\RequestStack
+   */
   protected $requestStack;
 
   /**