diff --git a/l10n_es_ticketbai/models/account_invoice.py b/l10n_es_ticketbai/models/account_invoice.py
index 08989f6a5d2..b07f6d20891 100644
--- a/l10n_es_ticketbai/models/account_invoice.py
+++ b/l10n_es_ticketbai/models/account_invoice.py
@@ -389,8 +389,8 @@ def validate_refund_invoices():
             self.sudo().filtered(
                 lambda x:
                 x.tbai_enabled and 'out_refund' == x.type and
-                not x.tbai_refund_type or
-                x.tbai_refund_type == RefundType.differences.value and
+                (not x.tbai_refund_type or
+                x.tbai_refund_type == RefundType.differences.value) and
                 x.date and x.date >= x.journal_id.tbai_active_date)
 
         validate_refund_invoices()