diff --git a/htdocs/core/class/conf.class.php b/htdocs/core/class/conf.class.php
index 3d6526690a7..ce726265006 100644
--- a/htdocs/core/class/conf.class.php
+++ b/htdocs/core/class/conf.class.php
@@ -235,7 +235,7 @@ class Conf
             $filesList = explode(":", $this->global->LOCAL_CONSTS_FILES);
             foreach ($filesList as $file) {
                 $file = dol_sanitizeFileName($file);
-                include_once DOL_DOCUMENT_ROOT."/".$file."/".$file."_consts.php"; // This file can run code like setting $this->global->XXX vars.
+                dol_include_once($file."/".$file."_consts.php"); // This file can run code like setting $this->global->XXX vars.
             }
         }