diff --git a/htdocs/webservices/server_order.php b/htdocs/webservices/server_order.php
index b6ded243233..ec9b46c49a2 100644
--- a/htdocs/webservices/server_order.php
+++ b/htdocs/webservices/server_order.php
@@ -374,7 +374,7 @@ $server->register(
  * @param	string		$ref_ext			Ref_ext
  * @return	array							Array result
  */
-function getOrder($authentication, $id = '', $ref = '', $ref_ext = '')
+function getOrder($authentication, $id = 0, $ref = '', $ref_ext = '')
 {
 	global $db, $conf;
 
@@ -806,7 +806,7 @@ function createOrder($authentication, $order)
  * @param	int			$id_warehouse		Id of warehouse to use for stock decrease
  * @return	array							Array result
  */
-function validOrder($authentication, $id = '', $id_warehouse = 0)
+function validOrder($authentication, $id = 0, $id_warehouse = 0)
 {
 	global $db, $conf, $langs;