diff --git a/simple_oauth.gemspec b/simple_oauth.gemspec
index 875340c..acbf11d 100644
--- a/simple_oauth.gemspec
+++ b/simple_oauth.gemspec
@@ -2,6 +2,7 @@
 require File.expand_path('../lib/simple_oauth/version', __FILE__)
 
 Gem::Specification.new do |spec|
+  spec.add_development_dependency 'bundler', '~> 1.0'
   spec.add_development_dependency 'mocha', '~> 0.9'
   spec.add_development_dependency 'rake', '~> 0.8'
   spec.add_development_dependency 'simplecov', '~> 0.4'