diff --git a/Classes/Domain/DoctrineRepository/Product/BeVariantRepository.php b/Classes/Domain/DoctrineRepository/Product/BeVariantRepository.php
index 8d554af..9f4c96a 100644
--- a/Classes/Domain/DoctrineRepository/Product/BeVariantRepository.php
+++ b/Classes/Domain/DoctrineRepository/Product/BeVariantRepository.php
@@ -50,7 +50,7 @@ public function addQuantityToStock(int $uid, int $quantity): void
             ->orWhere(
                 $queryBuilder->expr()->eq('l10n_parent', $queryBuilder->createNamedParameter($uid, Connection::PARAM_INT))
             )
-            ->set('stock', $currentStock - $quantity)
+            ->set('stock', $currentStock + $quantity)
             ->executeStatement();
     }