diff --git a/core/lib/Drupal/Core/Template/TwigPhpStorageCache.php b/core/lib/Drupal/Core/Template/TwigPhpStorageCache.php
index 85abe24..258aa36 100644
--- a/core/lib/Drupal/Core/Template/TwigPhpStorageCache.php
+++ b/core/lib/Drupal/Core/Template/TwigPhpStorageCache.php
@@ -27,12 +27,12 @@ class TwigPhpStorageCache implements \Twig_CacheInterface {
    *
    * @var \Drupal\Core\Cache\CacheBackendInterface
    */
-  protected $cache = NULL;
+  protected $cache;
 
   /**
    * The PhpStorage object used for storing the templates.
    *
-   * @var \Drupal\Core\PhpStorage\PhpStorageFactory
+   * @var \Drupal\Component\PhpStorage\PhpStorageInterface
    */
   protected $storage;
 
@@ -111,7 +111,7 @@ public function getTimestamp($key) {
       return $cache->data;
     }
     else {
-      return REQUEST_TIME;
+      return 0;
     }
   }