diff --git a/models/account_payment_order.py b/models/account_payment_order.py
index b4a6af41d38acaeaf8e86a68d874212a8fc833ab..3fc26cb07c32eb1a5f1ff2b15baf2a64ccbf141e 100644
--- a/models/account_payment_order.py
+++ b/models/account_payment_order.py
@@ -76,11 +76,3 @@ class AccountPaymentOrder(models.Model):
             'search_view_id': [search_id, 'search'],
             'domain': [['payment_order_id', '=', self.id]],
         }
-
-
-class AccountPaymentLine(models.Model):
-    _inherit = 'account.payment.line'
-
-    @api.multi
-    def draft2open_payment_line_check(self):
-        self.ensure_one()