diff --git a/addons/purchase/models/account_invoice.py b/addons/purchase/models/account_invoice.py
index 65c3a13e1ad..0f39a58045b 100644
--- a/addons/purchase/models/account_invoice.py
+++ b/addons/purchase/models/account_invoice.py
@@ -60,7 +60,7 @@ class AccountMove(models.Model):
         self.update(invoice_vals)
 
         # Copy purchase lines.
-        po_lines = self.purchase_id.order_line - self.line_ids.mapped('purchase_line_id')
+        po_lines = self.purchase_id.order_line - self.invoice_line_ids.mapped('purchase_line_id')
         for line in po_lines.filtered(lambda l: not l.display_type):
             self.invoice_line_ids += self.env['account.move.line'].new(
                 line._prepare_account_move_line(self)