diff --git a/lib/valanga.rb b/lib/valanga.rb
index <HASH>..<HASH> 100644
--- a/lib/valanga.rb
+++ b/lib/valanga.rb
@@ -7,3 +7,4 @@ require "valanga/music/groovin"
 require "valanga/music/collete"
 require "valanga/music_attribute"
 require "valanga/difficulty/basic"
+require "valanga/difficulty/medium"
require "valanga/difficulty/medium"