diff --git a/lib/ace/filters/image_thumbnailer.rb b/lib/ace/filters/image_thumbnailer.rb
index f75aba0..1f049e4 100644
--- a/lib/ace/filters/image_thumbnailer.rb
+++ b/lib/ace/filters/image_thumbnailer.rb
@@ -12,12 +12,11 @@ require "nokogiri"
 #   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)
       @file_name ||= file_name
-      @thumb_path ||= file_name.gsub(/\.([^\.]*)$/, '_thumb.\1')
+      @thumb_path ||= file_name.gsub(/content\/(.+)\.([^\.]*)$/, 'output/\1_thumb.\2')
     end
 
     def thumb_server_path
diff --git a/lib/ace/version.rb b/lib/ace/version.rb
index 34dbf4c..8cdb90b 100644
--- a/lib/ace/version.rb
+++ b/lib/ace/version.rb
@@ -1,5 +1,5 @@
 # encoding: utf-8
 
 module Ace
-  VERSION = "0.4.3"
+  VERSION = "0.4.4"
 end