diff -u b/core/includes/theme.inc b/core/includes/theme.inc
--- b/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1514,6 +1514,7 @@
     '#height' => 16,
     '#alt' => $text,
   );
+  $variables['attributes']['class'] = array('feed-icon');
   // Stripping tags because that's what l() used to do.
   $variables['attributes']['title'] = strip_tags($text);
 }