diff --git a/src/CommandSubscriber.php b/src/CommandSubscriber.php
index ef282bcac..569c7c909 100644
--- a/src/CommandSubscriber.php
+++ b/src/CommandSubscriber.php
@@ -21,17 +21,17 @@ public function __construct(private Connection $connection)
     {
     }
 
-    public function commandStarted(CommandStartedEvent $event)
+    public function commandStarted(CommandStartedEvent $event): void
     {
         $this->commands[$event->getOperationId()] = $event;
     }
 
-    public function commandFailed(CommandFailedEvent $event)
+    public function commandFailed(CommandFailedEvent $event): void
     {
         $this->logQuery($event);
     }
 
-    public function commandSucceeded(CommandSucceededEvent $event)
+    public function commandSucceeded(CommandSucceededEvent $event): void
     {
         $this->logQuery($event);
     }