diff --git a/pos_orderline_absolute_discount/models/pos_order_model.py b/pos_orderline_absolute_discount/models/pos_order_model.py
index 07e07d034a..45a635b103 100644
--- a/pos_orderline_absolute_discount/models/pos_order_model.py
+++ b/pos_orderline_absolute_discount/models/pos_order_model.py
@@ -45,29 +45,30 @@ class PosOrderLine(models.Model):
         "price_unit", "tax_ids", "qty", "discount", "product_id", "absolute_discount"
     )
     def _compute_amount_line_all(self):
-        super(PosOrderLine, self)._compute_amount_line_all()
-        for line in self:
-            fpos = line.order_id.fiscal_position_id
-            tax_ids_after_fiscal_position = (
-                fpos.map_tax(line.tax_ids, line.product_id, line.order_id.partner_id)
-                if fpos
-                else line.tax_ids
+        self.ensure_one()
+        res = super(PosOrderLine, self)._compute_amount_line_all()
+        fpos = self.order_id.fiscal_position_id
+        tax_ids_after_fiscal_position = (
+            fpos.map_tax(self.tax_ids, self.product_id, self.order_id.partner_id)
+            if fpos
+            else self.tax_ids
+        )
+        if self.absolute_discount:
+            price = self.price_unit - self.absolute_discount
+            taxes = tax_ids_after_fiscal_position.compute_all(
+                price,
+                self.order_id.pricelist_id.currency_id,
+                self.qty,
+                product=self.product_id,
+                partner=self.order_id.partner_id,
             )
-            if line.absolute_discount:
-                price = line.price_unit - line.absolute_discount
-                taxes = tax_ids_after_fiscal_position.compute_all(
-                    price,
-                    line.order_id.pricelist_id.currency_id,
-                    line.qty,
-                    product=line.product_id,
-                    partner=line.order_id.partner_id,
-                )
-                line.update(
-                    {
-                        "price_subtotal_incl": taxes["total_included"],
-                        "price_subtotal": taxes["total_excluded"],
-                    }
-                )
+            res.update(
+                {
+                    "price_subtotal_incl": taxes["total_included"],
+                    "price_subtotal": taxes["total_excluded"],
+                }
+            )
+        return res
 
     @api.onchange("qty", "discount", "price_unit", "tax_ids", "absolute_discount")
     def _onchange_qty(self):