diff --git a/lib/comments.php b/lib/comments.php
index 70a51fc..3b1f96f 100644
--- a/lib/comments.php
+++ b/lib/comments.php
@@ -42,8 +42,10 @@ class Roots_Walker_Comment extends Walker_Comment {
   }
 }
 
-function roots_get_avatar($avatar) {
+function roots_get_avatar($avatar, $type) {
+  if (!is_object($type)) { return $avatar; }
+
   $avatar = str_replace("class='avatar", "class='avatar pull-left media-object", $avatar);
   return $avatar;
 }
-add_filter('get_avatar', 'roots_get_avatar');
+add_filter('get_avatar', 'roots_get_avatar', 10, 2);