diff --git a/addons/sale/models/sale.py b/addons/sale/models/sale.py
index 0836ec09673..69600688519 100644
--- a/addons/sale/models/sale.py
+++ b/addons/sale/models/sale.py
@@ -1515,7 +1515,20 @@ class SaleOrderLine(models.Model):
                     # `price_reduce_taxexcl` cannot be used as it is computed from `price_subtotal` field. (see upper Note)
                     price_subtotal = line.tax_id.compute_all(price_subtotal)['total_excluded']
 
-                amount_to_invoice = price_subtotal - line.untaxed_amount_invoiced
+                if any(line.invoice_lines.mapped(lambda l: l.discount != line.discount)):
+                    # In case of re-invoicing with different discount we try to calculate manually the
+                    # remaining amount to invoice
+                    amount = 0
+                    for l in line.invoice_lines:
+                        if len(l.tax_ids.filtered(lambda tax: tax.price_include)) > 0:
+                            amount += l.tax_ids.compute_all(l.currency_id._convert(l.price_unit, line.currency_id, line.company_id, l.date or fields.Date.today(), round=False) * l.quantity)['total_excluded']
+                        else:
+                            amount += l.currency_id._convert(l.price_unit, line.currency_id, line.company_id, l.date or fields.Date.today(), round=False) * l.quantity
+
+                    amount_to_invoice = max(price_subtotal - amount, 0)
+                else:
+                    amount_to_invoice = price_subtotal - line.untaxed_amount_invoiced
+
             line.untaxed_amount_to_invoice = amount_to_invoice
 
     def _prepare_invoice_line(self, **optional_values):