diff --git a/.gitignore b/.gitignore
index 7422f56..86f729a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,5 @@
 *.gem
 nbproject
 doc/
-rdoc/
\ No newline at end of file
+rdoc/
+Gemfile.lock
\ No newline at end of file
diff --git a/Gemfile b/Gemfile
index 0f2ca40..81136a7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,3 +2,7 @@
 source "http://rubygems.org"
 
 gemspec
+
+group :test, :development do
+  gem 'rdoc', '>= 2.4.2'
+end