diff --git a/http-cookie.gemspec b/http-cookie.gemspec
index 9620bb0..b680b70 100644
--- a/http-cookie.gemspec
+++ b/http-cookie.gemspec
@@ -23,4 +23,5 @@ Gem::Specification.new do |gem|
   gem.require_paths = ["lib"]
 
   gem.add_runtime_dependency("domain_name", ["~> 0.5"])
+  gem.add_development_dependency("bundler", [">= 1.2.0"])
 end