diff --git a/htdocs/install/etape1.php b/htdocs/install/etape1.php
index 9b8578d6568..f40623f9efd 100644
--- a/htdocs/install/etape1.php
+++ b/htdocs/install/etape1.php
@@ -505,7 +505,7 @@ pFooter($error,$setuplang,'jsinfo');
 function write_conf_file($conffile)
 {
 	global $conf,$langs;
-	global $_POST,$main_dir,$main_data_dir;
+	global $_POST,$main_dir,$main_data_dir,$main_force_https;
 	global $dolibarr_main_url_root,$dolibarr_main_document_root,$dolibarr_main_data_root,$dolibarr_main_db_host;
 	global $dolibarr_main_db_port,$dolibarr_main_db_name,$dolibarr_main_db_user,$dolibarr_main_db_pass;
 	global $dolibarr_main_db_type,$dolibarr_main_db_character_set,$dolibarr_main_db_collation,$dolibarr_main_authentication;