diff --git a/bin/dither/dither.rb b/bin/dither/dither.rb
index c71a049..b0095e8 100644
--- a/bin/dither/dither.rb
+++ b/bin/dither/dither.rb
@@ -30,6 +30,7 @@ get "/*" do |path|
   convert.background("white")
   convert.layers("flatten")
   convert.strip
+  convert.auto_orient
 
   if geometry
     if geometry.match?(/^\d+x\d+$/)