diff --git a/lib/rb/thrift.gemspec b/lib/rb/thrift.gemspec
index 7481a29..d0366a7 100644
--- a/lib/rb/thrift.gemspec
+++ b/lib/rb/thrift.gemspec
@@ -27,7 +27,7 @@
 
   s.require_paths = %w[lib ext]
 
-  s.add_development_dependency 'bundler',            '~> 1.11'
+  s.add_development_dependency 'bundler',            '>= 1.11'
   s.add_development_dependency 'pry',                '~> 0.11.3'
   s.add_development_dependency 'pry-byebug',         '~> 3.6'
   s.add_development_dependency 'pry-stack_explorer', '~> 0.4.9.2'
@@ -35,6 +35,7 @@
   s.add_development_dependency 'rack-test',          '~> 0.8.3'
   s.add_development_dependency 'rake',               '~> 12.3'
   s.add_development_dependency 'rspec',              '~> 3.7'
+  s.add_development_dependency 'srv',                '~> 1.0'
   s.add_development_dependency 'thin',               '~> 1.7'
 end