diff --git a/app/models/post.rb b/app/models/post.rb
index 36522ae8735..9f0b520cfe7 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -255,7 +255,7 @@ class Post < ActiveRecord::Base
   end
 
   def self.white_listed_image_classes
-    @white_listed_image_classes ||= ['avatar', 'favicon', 'thumbnail', 'emoji']
+    @white_listed_image_classes ||= ['avatar', 'favicon', 'thumbnail', 'emoji', 'ytp-thumbnail-image']
   end
 
   def post_analyzer