diff --git a/htdocs/fourn/class/api_supplier_invoices.class.php b/htdocs/fourn/class/api_supplier_invoices.class.php
index f5b3afa4b18..b42c578a783 100644
--- a/htdocs/fourn/class/api_supplier_invoices.class.php
+++ b/htdocs/fourn/class/api_supplier_invoices.class.php
@@ -454,7 +454,8 @@ class SupplierInvoices extends DolibarrApi
         $paiement->amounts      = $amounts; // Array with all payments dispatching with invoice id
         $paiement->multicurrency_amounts = $multicurrency_amounts; // Array with all payments dispatching
         $paiement->paiementid = $paiementid;
-        $paiement->oper = dol_getIdFromCode($this->db, $paiementid, 'c_paiement', 'id', 'code', 1);
+        $paiement->paiementcode = dol_getIdFromCode($this->db, $paiementid, 'c_paiement', 'id', 'code', 1);
+        $paiement->oper = $paiement->paiementcode;	// For backward compatibility
         $paiement->num_payment = $num_payment;
         $paiement->note_public = $comment;