diff --git a/wp-includes/feed-rss.php b/wp-includes/feed-rss.php
index 51c15ec71..e5c2fe830 100644
--- a/wp-includes/feed-rss.php
+++ b/wp-includes/feed-rss.php
@@ -5,7 +5,7 @@
  * @package WordPress
  */
 
-header('Content-Type: ' . feed_content_type('rss') . '; charset=' . get_option('blog_charset'), true);
+header('Content-Type: ' . feed_content_type('rss-http') . '; charset=' . get_option('blog_charset'), true);
 $more = 1;
 
 echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>'; ?>
diff --git a/wp-includes/feed-rss2-comments.php b/wp-includes/feed-rss2-comments.php
index d5ea2cc5e..8232a0f17 100644
--- a/wp-includes/feed-rss2-comments.php
+++ b/wp-includes/feed-rss2-comments.php
@@ -5,7 +5,7 @@
  * @package WordPress
  */
 
-header('Content-Type: ' . feed_content_type('rss2') . '; charset=' . get_option('blog_charset'), true);
+header('Content-Type: ' . feed_content_type('rss-http') . '; charset=' . get_option('blog_charset'), true);
 
 echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>';
 ?>
diff --git a/wp-includes/feed-rss2.php b/wp-includes/feed-rss2.php
index 01aa66616..c4299cbea 100644
--- a/wp-includes/feed-rss2.php
+++ b/wp-includes/feed-rss2.php
@@ -5,7 +5,7 @@
  * @package WordPress
  */
 
-header('Content-Type: ' . feed_content_type('rss2') . '; charset=' . get_option('blog_charset'), true);
+header('Content-Type: ' . feed_content_type('rss-http') . '; charset=' . get_option('blog_charset'), true);
 $more = 1;
 
 echo '<?xml version="1.0" encoding="'.get_option('blog_charset').'"?'.'>'; ?>
diff --git a/wp-includes/feed.php b/wp-includes/feed.php
index bc094d524..74cb6b4a4 100644
--- a/wp-includes/feed.php
+++ b/wp-includes/feed.php
@@ -523,10 +523,11 @@ function feed_content_type( $type = '' ) {
 		$type = get_default_feed();
 
 	$types = array(
-		'rss'  => 'text/xml',
-		'rss2' => 'text/xml',
+		'rss'  => 'application/rss+xml',
+		'rss2' => 'application/rss+xml',
+		'rss-http'  => 'text/xml',
 		'atom' => 'application/atom+xml',
-		'rdf'  => 'application/rdf+xml',
+		'rdf'  => 'application/rdf+xml'
 	);
 
 	$content_type = ( !empty($types[$type]) ) ? $types[$type] : 'application/octet-stream';