diff --git a/htdocs/lib/functions.lib.php b/htdocs/lib/functions.lib.php
index 7d6fc9f3fd1..c5f2144ce8c 100644
--- a/htdocs/lib/functions.lib.php
+++ b/htdocs/lib/functions.lib.php
@@ -92,7 +92,7 @@ function GETPOST($paramname,$check='',$method=0)
  */
 function dol_getprefix()
 {
-    return dol_hash($_SERVER["SERVER_NAME"].$_SERVER["DOCUMENT_ROOT"].DOL_DOCUMENT_ROOT.DOL_URL_ROOT);
+    return md5($_SERVER["SERVER_NAME"].$_SERVER["DOCUMENT_ROOT"].DOL_DOCUMENT_ROOT.DOL_URL_ROOT);
 }
 
 /**