diff --git a/http-cookie.gemspec b/http-cookie.gemspec
index 4878df8..fabf3d6 100644
--- a/http-cookie.gemspec
+++ b/http-cookie.gemspec
@@ -25,5 +25,7 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency("domain_name", ["~> 0.5"])
   gem.add_development_dependency("bundler", [">= 1.2.0"])
   gem.add_development_dependency("test-unit", [">= 2.4.3"])
+  gem.add_development_dependency("rake", [">= 0.9.2.2"])
+  gem.add_development_dependency("rdoc", ["> 2.4.2"])
   gem.add_development_dependency("simplecov", [">= 0"])
 end