diff --git a/htdocs/core/tpl/login.tpl.php b/htdocs/core/tpl/login.tpl.php
index 55a5f6f608d..2e31abbc569 100644
--- a/htdocs/core/tpl/login.tpl.php
+++ b/htdocs/core/tpl/login.tpl.php
@@ -35,6 +35,8 @@ print '<!-- Includes for JQuery (Ajax library) -->'."\n";
 if (constant('JS_JQUERY_UI')) print '<link rel="stylesheet" type="text/css" href="'.JS_JQUERY_UI.'css/'.$jquerytheme.'/jquery-ui.min.css" />'."\n";  // JQuery
 else print '<link rel="stylesheet" type="text/css" href="'.DOL_URL_ROOT.'/includes/jquery/css/'.$jquerytheme.'/jquery-ui-latest.custom.css" />'."\n";    // JQuery
 // JQuery. Must be before other includes
+$ext='.js';
+if (isset($conf->global->MAIN_OPTIMIZE_SPEED) && ($conf->global->MAIN_OPTIMIZE_SPEED & 0x01)) $ext='.jgz';
 print '<!-- Includes JS for JQuery -->'."\n";
 if (constant('JS_JQUERY')) print '<script type="text/javascript" src="'.JS_JQUERY.'jquery.min.js"></script>'."\n";
 else print '<script type="text/javascript" src="'.DOL_URL_ROOT.'/includes/jquery/js/jquery-latest.min'.$ext.'"></script>'."\n";