diff --git a/bureau/class/config.php b/bureau/class/config.php
index 1149e504..1e0e5ef7 100644
--- a/bureau/class/config.php
+++ b/bureau/class/config.php
@@ -144,7 +144,7 @@ class DB_system extends DB_Sql {
 $db = new DB_system();
 
 // https: Redirection if not calling https://!fqdn or if https is forced
-if ((variable_get('force_https', '0', "This variable is set to 0 (default) if users can access the management desktop through HTTP, otherwise we force HTTPS")&&( $_SERVER["HTTPS"] != "on"))
+if ((variable_get('force_https', '0', "This variable is set to 0 (default) if users can access the management desktop through HTTP, otherwise we force HTTPS")&&(!isset($_SERVER["HTTPS"])|| ($_SERVER["HTTPS"] != "on")))
     ||(isset($_SERVER["HTTPS"]) && $_SERVER["HTTPS"] == "on" && $host != $L_FQDN)) {
     header("Location: https://$L_FQDN".$_SERVER['REQUEST_URI']);
     exit;