--- a/htdocs/install/etape5.php
+++ b/htdocs/install/etape5.php
@@ -28,6 +28,7 @@
 include_once("./inc.php");
 if (file_exists($conffile)) include_once($conffile);
 require_once($dolibarr_main_document_root . "/core/lib/admin.lib.php");
+require_once($dolibarr_main_document_root . "/core/lib/security.lib.php"); // for dol_hash
 
 
 $setuplang=isset($_POST["selectlang"])?$_POST["selectlang"]:(isset($_GET["selectlang"])?$_GET["selectlang"]:'auto');