diff --git a/vendor/magento/module-inventory-source-selection-api/Model/Algorithms/Result/GetDefaultSortedSourcesResult.php b/vendor/magento/module-inventory-source-selection-api/Model/Algorithms/Result/GetDefaultSortedSourcesResult.php
index c7f69e05512d..230f3ac40eac 100644
--- a/vendor/magento/module-inventory-source-selection-api/Model/Algorithms/Result/GetDefaultSortedSourcesResult.php
+++ b/vendor/magento/module-inventory-source-selection-api/Model/Algorithms/Result/GetDefaultSortedSourcesResult.php
@@ -96,7 +96,7 @@ public function execute(
         $itemsTdDeliver = [];
         foreach ($inventoryRequest->getItems() as $item) {
             $normalizedSku = $this->normalizeSku($item->getSku());
-            $itemsTdDeliver[$normalizedSku] = $item->getQty();
+            $itemsTdDeliver[$normalizedSku] = ($itemsTdDeliver[$normalizedSku] ?? 0) + $item->getQty();
         }
 
         $sortedSourceCodes = [];