diff --git a/htdocs/fourn/class/fournisseur.facture.class.php b/htdocs/fourn/class/fournisseur.facture.class.php
index 019b36f7fdf..5b26339c8c8 100644
--- a/htdocs/fourn/class/fournisseur.facture.class.php
+++ b/htdocs/fourn/class/fournisseur.facture.class.php
@@ -1525,7 +1525,7 @@ class FactureFournisseur extends CommonInvoice
         $object->statut=0;
 
         // Clear fields
-        $object->ref=$langs->trans("CopyOf").' '.$object->ref;
+        $object->ref_supplier=$langs->trans("CopyOf").' '.$object->ref_supplier;
         $object->author             = $user->id;
         $object->user_valid         = '';
         $object->fk_facture_source  = 0;