diff --git a/app/uploaders/wallpaper_uploader.rb b/app/uploaders/wallpaper_uploader.rb
index 4d78e6e800af69a8675c1ac9c408bc5c1fccae8d..c913436d127a4afe7f1cf2f100dd2941f749d8bc 100644
--- a/app/uploaders/wallpaper_uploader.rb
+++ b/app/uploaders/wallpaper_uploader.rb
@@ -19,7 +19,10 @@ class WallpaperUploader < CarrierWave::Uploader::Base
 
   def darken
     manipulate! do |img|
-      img.brightness_contrast "-40x-50"
+      # img.brightness_contrast "-40x-50"
+      # thanks, heroku.
+      img.modulate "40,40"
+
       img = yield(img) if block_given?
       img
     end