diff --git a/addons/purchase/models/account_invoice.py b/addons/purchase/models/account_invoice.py
index e7e801429d1..a820c28923d 100644
--- a/addons/purchase/models/account_invoice.py
+++ b/addons/purchase/models/account_invoice.py
@@ -101,8 +101,8 @@ class AccountInvoice(models.Model):
     @api.onchange('invoice_line_ids')
     def _onchange_origin(self):
         purchase_ids = self.invoice_line_ids.mapped('purchase_id')
-        if purchase_ids:
-            self.origin = ', '.join(purchase_ids.mapped('name'))
+        self.origin = ', '.join(purchase_ids.mapped('name'))
+        self.reference = ', '.join(purchase_ids.filtered('partner_ref').mapped('partner_ref'))
 
     @api.onchange('partner_id', 'company_id')
     def _onchange_partner_id(self):