diff --git a/app/code/Magento/Catalog/Model/ProductLink/Repository.php b/app/code/Magento/Catalog/Model/ProductLink/Repository.php
index d58fdae3ae7a5..0268bc471722e 100644
--- a/app/code/Magento/Catalog/Model/ProductLink/Repository.php
+++ b/app/code/Magento/Catalog/Model/ProductLink/Repository.php
@@ -139,7 +139,7 @@ public function save(\Magento\Catalog\Api\Data\ProductLinkInterface $entity)
                 . 'Please ensure the parent product SKU is provided and try again.'
             ));
         }
-        if (!$entity->getLinkedProductSku()) {
+        if ($entity->getLinkedProductSku() === null || $entity->getLinkedProductSku() === '') {
             throw new CouldNotSaveException(__('The linked product SKU is invalid. Verify the data and try again.'));
         }
         $linkedProduct = $this->productRepository->get($entity->getLinkedProductSku());