diff --git a/app/code/Magento/Wishlist/Model/Wishlist.php b/app/code/Magento/Wishlist/Model/Wishlist.php
index 9eb4e1f5ebcd2..d6284f32c4f5e 100644
--- a/app/code/Magento/Wishlist/Model/Wishlist.php
+++ b/app/code/Magento/Wishlist/Model/Wishlist.php
@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Wishlist\Model;
 
 use Magento\Catalog\Api\ProductRepositoryInterface;
@@ -637,6 +639,7 @@ public function updateItem($itemId, $buyRequest, $params = null)
         $item = null;
         if ($itemId instanceof Item) {
             $item = $itemId;
+            $itemId = $item->getId();
         } else {
             $item = $this->getItem((int)$itemId);
         }