diff --git a/lib/ace/filters/image_thumbnailer.rb b/lib/ace/filters/image_thumbnailer.rb
index b4d5774..f75aba0 100644
--- a/lib/ace/filters/image_thumbnailer.rb
+++ b/lib/ace/filters/image_thumbnailer.rb
@@ -11,6 +11,8 @@ require "nokogiri"
 # class Post < Ace::Item
 #   before Ace::ImageThumbnailerFilter, default_thumb_size: 550
 # end
+
+# FIXME: generate thumbnail to output/, not to content/ !!!
 module Ace
   class ImageThumbnailerFilter < Filter
     def thumb_path(file_name)