diff --git a/lib/puppet/parser/functions/md5.rb b/lib/puppet/parser/functions/md5.rb
index 864aae048..d1e1efae2 100644
--- a/lib/puppet/parser/functions/md5.rb
+++ b/lib/puppet/parser/functions/md5.rb
@@ -1,5 +1,5 @@
-require 'md5'
+require 'digest/md5'
 
 Puppet::Parser::Functions::newfunction(:md5, :type => :rvalue, :doc => "Returns a MD5 hash value from a provided string.") do |args|
       Digest::MD5.hexdigest(args[0])
 end