diff --git a/core/modules/aggregator/src/FeedStorage.php b/core/modules/aggregator/src/FeedStorage.php
index 90179748a836f7e66915921c07dcc4f538ea1a16..ad9bfa3f634de6972e2ac54343cc046db29beca7 100644
--- a/core/modules/aggregator/src/FeedStorage.php
+++ b/core/modules/aggregator/src/FeedStorage.php
@@ -17,24 +17,6 @@
  */
 class FeedStorage extends SqlContentEntityStorage implements FeedStorageInterface {
 
-  /**
-   * {@inheritdoc}
-   */
-  public function getFeedDuplicates(FeedInterface $feed) {
-    $query = \Drupal::entityQuery('aggregator_feed');
-
-    $or_condition = $query->orConditionGroup()
-      ->condition('title', $feed->label())
-      ->condition('url', $feed->getUrl());
-    $query->condition($or_condition);
-
-    if ($feed->id()) {
-      $query->condition('fid', $feed->id(), '<>');
-    }
-
-    return $this->loadMultiple($query->execute());
-  }
-
   /**
    * {@inheritdoc}
    */
diff --git a/core/modules/aggregator/src/FeedStorageInterface.php b/core/modules/aggregator/src/FeedStorageInterface.php
index 87875b96c6ce40f378eb2d6da1d21a257718b960..185e66cb8b3295ed3283040726db6c9b176db177 100644
--- a/core/modules/aggregator/src/FeedStorageInterface.php
+++ b/core/modules/aggregator/src/FeedStorageInterface.php
@@ -15,17 +15,6 @@
  */
 interface FeedStorageInterface extends EntityStorageInterface {
 
-  /**
-   * Provides a list of duplicate feeds.
-   *
-   * @param \Drupal\aggregator\Entity\FeedInterface $feed
-   *   The feed entity.
-   *
-   * @return
-   *   An array with the list of duplicated feeds.
-   */
-  public function getFeedDuplicates(FeedInterface $feed);
-
   /**
    * Returns the fids of feeds that need to be refreshed.
    *