diff --git a/sale.py b/sale.py
index 5c93d1e92d..3d50960faf 100644
--- a/sale.py
+++ b/sale.py
@@ -1298,7 +1298,7 @@ class SaleLine(ModelSQL, ModelView):
         ignored_ids = set(
             l.id for i in line.sale.invoices_ignored for l in i.lines)
         for invoice_line in line.invoice_lines:
-            if ((invoice_lines.invoice and
+            if ((invoice_line.invoice and
                     invoice_line.invoice.state != 'cancel') or
                 invoice_line.id in ignored_ids):
                 quantity -= uom_obj.compute_qty(