diff --git a/addons/point_of_sale/models/pos_order.py b/addons/point_of_sale/models/pos_order.py
index f38e19becaa..dd970f4f146 100644
--- a/addons/point_of_sale/models/pos_order.py
+++ b/addons/point_of_sale/models/pos_order.py
@@ -856,7 +856,7 @@ class PosOrder(models.Model):
                             # a serialnumber always has a quantity of 1 product, a lot number takes the full quantity of the order line
                             qty = 1.0
                             if stock_production_lot.product_id.tracking == 'lot':
-                                qty = pos_pack_lot.pos_order_line_id.qty
+                                qty = abs(pos_pack_lot.pos_order_line_id.qty)
                             qty_done += qty
                             pack_lots.append({'lot_id': stock_production_lot.id, 'qty': qty})
                         else: