diff --git a/sale.py b/sale.py
index b1c790d..2e608a3 100644
--- a/sale.py
+++ b/sale.py
@@ -48,7 +48,7 @@ class Sale:
             if sale.invoices:
                 to_delete_invoices += sale.invoices
 
-            if sale.shipments or sale.shipments_returns:
+            if sale.shipments or sale.shipment_returns:
                 to_delete_shipments += sale.shipments
                 to_delete_shipments_return += sale.shipment_returns