diff --git a/htdocs/commande/class/api_orders.class.php b/htdocs/commande/class/api_orders.class.php
index 298333e1fb8..60f1be1e00c 100644
--- a/htdocs/commande/class/api_orders.class.php
+++ b/htdocs/commande/class/api_orders.class.php
@@ -490,7 +490,7 @@ class Orders extends DolibarrApi
 		    throw new RestException(500, 'Error nothing done. May be object is already validated');
 		}
 		if ($result < 0) {
-		    throw new RestException(500, 'Error when validating Order: '.$this->commande->error);
+		    throw new RestException(304, 'Error when validating Order: '.$this->commande->error);
 		}
 	$result = $this->commande->fetch($id);
         if( ! $result ) {