diff --git a/account_banking_mandate/models/account_invoice.py b/account_banking_mandate/models/account_invoice.py
index 45c571f59..5b82b9707 100644
--- a/account_banking_mandate/models/account_invoice.py
+++ b/account_banking_mandate/models/account_invoice.py
@@ -73,10 +73,12 @@ class AccountInvoice(models.Model):
     @api.onchange('partner_id', 'company_id')
     def _onchange_partner_id(self):
         """Select by default the first valid mandate of the partner"""
-        super(AccountInvoice, self)._onchange_partner_id()
+        res = super(AccountInvoice, self)._onchange_partner_id()
         self.set_mandate()
+        return res
 
     @api.onchange('payment_mode_id')
     def payment_mode_id_change(self):
-        super(AccountInvoice, self).payment_mode_id_change()
+        res = super(AccountInvoice, self).payment_mode_id_change()
         self.set_mandate()
+        return res