diff --git a/core/lib/Drupal/Core/Cache/DatabaseBackend.php b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
index d1b6975..06c5dc2 100644
--- a/core/lib/Drupal/Core/Cache/DatabaseBackend.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
@@ -190,7 +190,7 @@ public function setMultiple(array $items) {
    *
    * @see \Drupal\Core\Cache\CacheBackendInterface::setMultiple()
    */
-  public function doSetMultiple(array $items) {
+  protected function doSetMultiple(array $items) {
     $values = array();
 
     foreach ($items as $cid => $item) {