diff --git a/htdocs/install/etape1.php b/htdocs/install/etape1.php
index 4002605b51c..152087f0462 100644
--- a/htdocs/install/etape1.php
+++ b/htdocs/install/etape1.php
@@ -134,7 +134,7 @@ if ($_POST["action"] == "set")
     
             if (file_exists("$conffile"))
             {
-                include_once("$conffile");
+                include("$conffile");	// On force rechargement. Ne pas mettre include_once !
                 print "<tr><td>".$langs->trans("ConfigurationSaving")."</td><td>".$langs->trans("OK")."</td>";
             }
             else
diff --git a/htdocs/install/inc.php b/htdocs/install/inc.php
index a75ecb9194c..9701454ca52 100644
--- a/htdocs/install/inc.php
+++ b/htdocs/install/inc.php
@@ -33,9 +33,12 @@ $conffile = "../conf/conf.php";
 if (file_exists($conffile))
 {
 	include_once($conffile);
-	require_once($dolibarr_main_document_root . "/conf/conf.class.php");
-	require_once($dolibarr_main_document_root . "/lib/databases/".$dolibarr_main_db_type.".lib.php");
-	$conf=new Conf();
+	if ($dolibarr_main_document_root)
+	{
+		require_once($dolibarr_main_document_root . "/conf/conf.class.php");
+		require_once($dolibarr_main_document_root . "/lib/databases/".$dolibarr_main_db_type.".lib.php");
+		$conf=new Conf();
+	}
 }
 if (! isset($dolibarr_main_db_prefix) || ! $dolibarr_main_db_prefix) $dolibarr_main_db_prefix='llx_'; 
 define('MAIN_DB_PREFIX',$dolibarr_main_db_prefix);