diff --git a/twhois.gemspec b/twhois.gemspec
index f37a67f..fa9f1ed 100644
--- a/twhois.gemspec
+++ b/twhois.gemspec
@@ -18,4 +18,10 @@ Gem::Specification.new do |s|
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")
   s.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   s.require_paths = ["lib"]
+  
+  s.add_runtime_dependency 'json_pure', '>= 1.0.0'
+  s.add_runtime_dependency 'hashie', '>= 1.0.0'
+  
+  s.add_development_dependency 'rspec', '>= 2.5.0'
+  s.add_development_dependency 'yard', '>= 0.6.4'
 end