diff --git a/addons/account_payment/wizard/account_payment_populate_statement.py b/addons/account_payment/wizard/account_payment_populate_statement.py
index cedfe55a2e5..b74ae87a685 100644
--- a/addons/account_payment/wizard/account_payment_populate_statement.py
+++ b/addons/account_payment/wizard/account_payment_populate_statement.py
@@ -95,6 +95,9 @@ class account_payment_populate_statement(osv.osv_memory):
                 }
                 voucher_id = voucher_obj.create(cr, uid, voucher_res, context=context)
                 voucher_line_dict =  False
+
+                # NOTE: we only check for lines on 'debit' as Payment Order only allow user
+                # to choose account.move.line with credit > 0, i.e payment will be on 'debit'
                 if result['value']['line_dr_ids']:
                     for line_dict in result['value']['line_dr_ids']:
                         move_line = move_line_obj.browse(cr, uid, line_dict['move_line_id'], context)