diff --git a/addons/account/models/account_move.py b/addons/account/models/account_move.py
index d919d2c95d8..e4866d516a0 100644
--- a/addons/account/models/account_move.py
+++ b/addons/account/models/account_move.py
@@ -1312,7 +1312,7 @@ class AccountMove(models.Model):
                 tax_key_add_base = tuple(move._get_tax_key_for_group_add_base(line))
                 if tax_key_add_base not in done_taxes:
                     if line.currency_id != self.company_id.currency_id:
-                        amount = self.company_id.currency_id._convert(line.tax_base_amount, line.currency_id, self.company_id, line.date)
+                        amount = self.company_id.currency_id._convert(line.tax_base_amount, line.currency_id, self.company_id, line.date or fields.Date.today())
                     else:
                         amount = line.tax_base_amount
                     res[line.tax_line_id.tax_group_id]['base'] += amount