diff --git a/rma_sale/models/sale_order_line.py b/rma_sale/models/sale_order_line.py
index 2a6e1632..0d6bc41b 100644
--- a/rma_sale/models/sale_order_line.py
+++ b/rma_sale/models/sale_order_line.py
@@ -47,7 +47,7 @@ class SaleOrderLine(models.Model):
                                 " ".join(
                                     str(x)
                                     for x in [
-                                        inv.number for inv in sale.order_id.invoice_ids
+                                        inv.name for inv in sale.order_id.invoice_ids
                                     ]
                                 ),
                                 sale.product_id.name,