diff --git a/core/lib/Drupal/Core/Cache/NullBackend.php b/core/lib/Drupal/Core/Cache/NullBackend.php
index c3da5d7..0408fc3 100644
--- a/core/lib/Drupal/Core/Cache/NullBackend.php
+++ b/core/lib/Drupal/Core/Cache/NullBackend.php
@@ -42,7 +42,7 @@ class NullBackend implements CacheBackendInterface {
   /**
    * Implements Drupal\Core\Cache\CacheBackendInterface::set().
    */
-  function set($cid, $data, $expire = CACHE_PERMANENT) {}
+  function set($cid, $data, $expire = CACHE_PERMANENT, array $tags = array()) {}
 
   /**
    * Implements Drupal\Core\Cache\CacheBackendInterface::delete().
@@ -75,6 +75,11 @@ class NullBackend implements CacheBackendInterface {
   function garbageCollection() {}
 
   /**
+   * Implements Drupal\Core\Cache\CacheBackendInterface::invalidateTags().
+   */
+  public function invalidateTags(array $tags) {}
+
+  /**
    * Implements Drupal\Core\Cache\CacheBackendInterface::isEmpty().
    */
   function isEmpty() {