diff --git a/addons/account/models/account_invoice.py b/addons/account/models/account_invoice.py
index db4f72dcca6..9d9d9464ceb 100644
--- a/addons/account/models/account_invoice.py
+++ b/addons/account/models/account_invoice.py
@@ -1162,7 +1162,7 @@ class AccountInvoiceLine(models.Model):
         if not self.product_id:
             fpos = self.invoice_id.fiscal_position_id
             self.invoice_line_tax_ids = fpos.map_tax(self.account_id.tax_ids).ids
-        else:
+        elif not self.price_unit:
             self._set_taxes()
 
     @api.onchange('uom_id')