diff --git a/wp-blog-header.php b/wp-blog-header.php
index 19146199d7..df9335c9ee 100644
--- a/wp-blog-header.php
+++ b/wp-blog-header.php
@@ -89,8 +89,10 @@ if (!isset($doing_rss) || !$doing_rss) {
 	@header ('X-Pingback: ' . get_settings('siteurl') . '/xmlrpc.php');
 
 	// Support for Conditional GET
-	$client_last_modified = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
-	$client_etag = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
+	if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])) $client_last_modified = $_SERVER['HTTP_IF_MODIFIED_SINCE'];
+	else $client_last_modified = false;
+	if (isset($_SERVER['HTTP_IF_NONE_MATCH'])) $client_etag = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
+	else $client_etag = false;
 
 	if ( ($client_last_modified && $client_etag) ?
 	    (($client_last_modified == $wp_last_modified) && ($client_etag == $wp_etag)) :
diff --git a/wp-includes/template-functions-comment.php b/wp-includes/template-functions-comment.php
index 00b5f6ee87..e7fd17e9c8 100644
--- a/wp-includes/template-functions-comment.php
+++ b/wp-includes/template-functions-comment.php
@@ -216,16 +216,20 @@ function comment_time($d='') {
 }
 
 function comments_rss_link($link_text='Comments RSS', $commentsrssfilename = 'wp-commentsrss2.php') {
+	$url = comments_rss($commentsrssfilename);
+	echo "<a href='$url'>$link_text</a>";
+}
+
+function comments_rss($commentsrssfilename = 'wp-commentsrss2.php') {
 	global $id;
 	global $querystring_start, $querystring_equal, $querystring_separator;
 
 	if ('' != get_settings('permalink_structure')) {
-		$url = trailingslashit(get_permalink()) . 'rss2/';
+		$url = trailingslashit(get_permalink()) . 'feed/';
 	} else {
 		$url = get_settings('siteurl') . '/' . $commentsrssfilename.$querystring_start.'p'.$querystring_equal.$id;
 	}
-
-	echo "<a href='$url'>$link_text</a>";
+	return $url;
 }
 
 function comment_author_rss() {
diff --git a/wp-rss2.php b/wp-rss2.php
index bab2aae428..83714914f2 100644
--- a/wp-rss2.php
+++ b/wp-rss2.php
@@ -14,7 +14,9 @@ header('Content-type: text/xml', true);
 
 <!-- generator="wordpress/<?php echo $wp_version ?>" -->
 <rss version="2.0" 
-	xmlns:content="http://purl.org/rss/1.0/modules/content/">
+	xmlns:content="http://purl.org/rss/1.0/modules/content/"
+	xmlns:wfw="http://wellformedweb.org/CommentAPI/"
+>
 
 <channel>
 	<title><?php bloginfo_rss('name') ?></title>
@@ -38,7 +40,7 @@ header('Content-type: text/xml', true);
 		<description><?php the_excerpt_rss(get_settings('rss_excerpt_length'), 2) ?></description>
 		<content:encoded><![CDATA[<?php the_content('', 0, '') ?>]]></content:encoded>
 <?php endif; ?>
-		
+		<wfw:commentRSS><?php echo comments_rss(); ?></wfw:commentRSS>
 	</item>
 	<?php $items_count++; if (($items_count == get_settings('posts_per_rss')) && empty($m)) { break; } } } ?>
 </channel>