diff --git a/wp-content/themes/twentyten/header.php b/wp-content/themes/twentyten/header.php
index 7d36ce2369..f9ba8c8009 100644
--- a/wp-content/themes/twentyten/header.php
+++ b/wp-content/themes/twentyten/header.php
@@ -35,7 +35,7 @@
 	?></title>
 	<link rel="profile" href="http://gmpg.org/xfn/11" />
 	<link rel="stylesheet" type="text/css" media="all" href="<?php bloginfo( 'stylesheet_url' ); ?>" />
-	<?php if ( is_singular() ) wp_enqueue_script( 'comment-reply' ); ?>
+	<?php if ( is_singular() && get_option('thread_comments') ) wp_enqueue_script( 'comment-reply' ); ?>
 	<link rel="pingback" href="<?php bloginfo( 'pingback_url' ); ?>" />
 	<?php wp_head(); ?>
 </head>