diff --git a/htdocs/expedition/card.php b/htdocs/expedition/card.php
index 384f2cdde3d..f79e4becd9d 100644
--- a/htdocs/expedition/card.php
+++ b/htdocs/expedition/card.php
@@ -1197,7 +1197,7 @@ if ($action == 'create') {
 					if (count($warehousePicking) == 1 || !($line->fk_product > 0) || empty($conf->stock->enabled)) {     // If warehouse was already selected or if product is not a predefined, we go into this part with no multiwarehouse selection
 						print '<!-- Case warehouse already known or product not a predefined product -->';
 						//ship from preselected location
-						$stock = +  isSET($product->stock_warehouse[$warehouse_id]->real) ? $product->stock_warehouse[$warehouse_id]->real : 0; // Convert to number
+						$stock = +  isset($product->stock_warehouse[$warehouse_id]->real) ? $product->stock_warehouse[$warehouse_id]->real : 0; // Convert to number
 						$deliverableQty = min($quantityToBeDelivered, $stock);
 						if ($deliverableQty < 0) {
 							$deliverableQty = 0;