diff --git a/addons/sale/wizard/sale_make_invoice_advance.py b/addons/sale/wizard/sale_make_invoice_advance.py
index 698f41995f5..08d703256bf 100644
--- a/addons/sale/wizard/sale_make_invoice_advance.py
+++ b/addons/sale/wizard/sale_make_invoice_advance.py
@@ -104,12 +104,14 @@ class SaleAdvancePaymentInv(models.TransientModel):
         return invoice_vals
 
     def _get_advance_details(self, order):
+        context = {'lang': order.partner_id.lang}
         if self.advance_payment_method == 'percentage':
             amount = order.amount_untaxed * self.amount / 100
             name = _("Down payment of %s%%") % (self.amount)
         else:
             amount = self.fixed_amount
             name = _('Down Payment')
+        del context
 
         return amount, name
 
@@ -130,6 +132,7 @@ class SaleAdvancePaymentInv(models.TransientModel):
         return invoice
 
     def _prepare_so_line(self, order, analytic_tag_ids, tax_ids, amount):
+        context = {'lang': order.partner_id.lang}
         so_values = {
             'name': _('Down Payment: %s') % (time.strftime('%m %Y'),),
             'price_unit': amount,
@@ -143,6 +146,7 @@ class SaleAdvancePaymentInv(models.TransientModel):
             'is_downpayment': True,
             'sequence': order.order_line and order.order_line[-1].sequence + 1 or 10,
         }
+        del context
         return so_values
 
     def create_invoices(self):
@@ -167,14 +171,12 @@ class SaleAdvancePaymentInv(models.TransientModel):
                     raise UserError(_("The product used to invoice a down payment should be of type 'Service'. Please use another product or update this product."))
                 taxes = self.product_id.taxes_id.filtered(lambda r: not order.company_id or r.company_id == order.company_id)
                 tax_ids = order.fiscal_position_id.map_tax(taxes, self.product_id, order.partner_shipping_id).ids
-                context = {'lang': order.partner_id.lang}
                 analytic_tag_ids = []
                 for line in order.order_line:
                     analytic_tag_ids = [(4, analytic_tag.id, None) for analytic_tag in line.analytic_tag_ids]
 
                 so_line_values = self._prepare_so_line(order, analytic_tag_ids, tax_ids, amount)
                 so_line = sale_line_obj.create(so_line_values)
-                del context
                 self._create_invoice(order, so_line, amount)
         if self._context.get('open_invoices', False):
             return sale_orders.action_view_invoice()