diff --git a/addons/account/models/account_reconcile_model.py b/addons/account/models/account_reconcile_model.py
index 6b39f02fcf545a44d62b2762e89d426f3954f564..651001f2699edbedfc56d59214cab082b17ae5fc 100644
--- a/addons/account/models/account_reconcile_model.py
+++ b/addons/account/models/account_reconcile_model.py
@@ -218,7 +218,7 @@ class AccountReconcileModel(models.Model):
     match_partner_category_ids = fields.Many2many('res.partner.category', string='Restrict Partner Categories to',
         help='The reconciliation model will only be applied to the selected customer/vendor categories.')
 
-    line_ids = fields.One2many('account.reconcile.model.line', 'model_id')
+    line_ids = fields.One2many('account.reconcile.model.line', 'model_id', copy=True)
     partner_mapping_line_ids = fields.One2many(string="Partner Mapping Lines",
                                                comodel_name='account.reconcile.model.partner.mapping',
                                                inverse_name='model_id',