diff --git a/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearch.php b/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearch.php
index b1a2e81..995ecd4 100644
--- a/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearch.php
+++ b/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearch.php
@@ -292,7 +292,7 @@ protected function addNodeRankings(SelectExtender $query) {
   public function updateIndex() {
     $limit = (int) $this->searchSettings->get('index.cron_limit');
 
-    $result = $this->database->queryRange("SELECT n.nid FROM {node} n LEFT JOIN {search_dataset} d ON d.type = :type AND d.sid = n.nid WHERE d.sid IS NULL OR d.reindex <> 0 ORDER BY d.reindex ASC, n.nid ASC", 0, $limit, array(':type' => $this->getPluginId()), array('target' => 'slave'));
+    $result = $this->database->queryRange("SELECT DISTINCT n.nid FROM {node} n LEFT JOIN {search_dataset} d ON d.type = :type AND d.sid = n.nid WHERE d.sid IS NULL OR d.reindex <> 0 ORDER BY d.reindex ASC, n.nid ASC", 0, $limit, array(':type' => $this->getPluginId()), array('target' => 'slave'));
     $nids = $result->fetchCol();
     if (!$nids) {
       return;