diff --git a/s3sync.rb b/s3sync.rb
index c80e828..82d87c8 100644
--- a/s3sync.rb
+++ b/s3sync.rb
@@ -20,7 +20,7 @@ module S3sync
   require 'getoptlong'
   #require 'generator' # http://www.ruby-doc.org/stdlib/libdoc/generator/rdoc/classes/Generator.html
   require 'thread_generator' # memory doesn't leak with this one, at least nothing near as bad
-  require 'md5'
+  require 'digest/md5'
   require 'tempfile'
   require 's3try'