diff --git a/addons/payment/models/account_payment.py b/addons/payment/models/account_payment.py
index cb416b81c14..33823eeadc8 100644
--- a/addons/payment/models/account_payment.py
+++ b/addons/payment/models/account_payment.py
@@ -44,8 +44,8 @@ class AccountPayment(models.Model):
 
     def _compute_amount_available_for_refund(self):
         for payment in self:
-            tx = payment.payment_transaction_id
-            if tx.acquirer_id.sudo().support_refund and tx.operation != 'refund':
+            tx_sudo = payment.payment_transaction_id.sudo()
+            if tx_sudo.acquirer_id.support_refund and tx_sudo.operation != 'refund':
                 # Only consider refund transactions that are confirmed by summing the amounts of
                 # payments linked to such refund transactions. Indeed, should a refund transaction
                 # be stuck forever in a transient state (due to webhook failure, for example), the