@ -191,7 +191,7 @@ class AccountAgedTrialBalanceWebkit(PartnersOpenInvoicesWebkit):
reference_line = sale_lines[0]
elif len(refund_lines) == 1:
reference_line = refund_lines[0]
key = line.get('date_maturity', reference_line['ldate'])
key = line.get('date_maturity', ldate')
return self._compute_delay_from_key(key,
reference_line,
end_date)