Index: wp-content/themes/twentyfifteen/header.php
===================================================================
--- wp-content/themes/twentyfifteen/header.php	(revision 30030)
+++ wp-content/themes/twentyfifteen/header.php	(working copy)
@@ -19,6 +19,7 @@
 	<!--[if lt IE 9]>
 	<script src="<?php echo get_template_directory_uri(); ?>/js/html5.js"></script>
 	<![endif]-->
+	<script>(function(H){H.className=H.className.replace(/\bno-js\b/,'js')})(document.documentElement);</script>
 	<?php wp_head(); ?>
 </head>
 
Index: wp-content/themes/twentyfifteen/js/functions.js
===================================================================
--- wp-content/themes/twentyfifteen/js/functions.js	(revision 30030)
+++ wp-content/themes/twentyfifteen/js/functions.js	(working copy)
@@ -8,8 +8,6 @@
 ( function( $ ) {
 	var $body, $window, sidebar, toolbarOffset;
 
-	$( 'html' ).removeClass( 'no-js' );
-
 	// Add dropdown toggle that display child menu items.
 	$( '.main-navigation .page_item_has_children > a, .main-navigation .menu-item-has-children > a' ).after( '<button class="dropdown-toggle" aria-expanded="false">' + screenReaderText.expand + '</button>' );