diff --git a/Gemfile b/Gemfile
index b6051aa..7c60b73 100644
--- a/Gemfile
+++ b/Gemfile
@@ -69,6 +69,7 @@ end
 
 group :development do
   gem "rdoc", ">= 2.4.2"
+  gem "yard"
 end
 
 group :test do