diff --git a/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php b/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php
index 8e3bf2e69bead..d27e85da73323 100644
--- a/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php
+++ b/src/Symfony/Component/HttpKernel/HttpCache/HttpCache.php
@@ -91,6 +91,7 @@ public function __construct(HttpKernelInterface $kernel, StoreInterface $store,
             'stale_if_error'         => 60,
         ), $options);
         $this->esi = $esi;
+        $this->traces = array();
     }
 
     /**