diff --git a/core/lib/Drupal/Core/Cache/DatabaseCacheTagsChecksum.php b/core/lib/Drupal/Core/Cache/DatabaseCacheTagsChecksum.php
index b6d9161b4e4..cc882eead16 100644
--- a/core/lib/Drupal/Core/Cache/DatabaseCacheTagsChecksum.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseCacheTagsChecksum.php
@@ -99,9 +99,15 @@ class DatabaseCacheTagsChecksum implements CacheTagsChecksumInterface, CacheTags
   }
 
   /**
-   * {@inheritdoc}
+   * Calculates the current checksum for a given set of tags.
+   *
+   * @param array $tags
+   *   The array of tags to calculate the checksum for.
+   *
+   * @return int
+   *   The calculated checksum.
    */
-  public function calculateChecksum(array $tags) {
+  protected function calculateChecksum(array $tags) {
     $checksum = 0;
 
     $query_tags = array_diff($tags, array_keys($this->tagCache));