diff --git a/twitter.gemspec b/twitter.gemspec
index bbdb5de90..7fa76665f 100644
--- a/twitter.gemspec
+++ b/twitter.gemspec
@@ -10,7 +10,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency('simplecov', '~> 0.4')
   s.add_development_dependency('webmock', '~> 1.6')
   s.add_development_dependency('yard', '~> 0.6')
-  s.add_development_dependency('ZenTest', '~> 4.4')
+  s.add_development_dependency('ZenTest', '~> 4.5')
   s.add_runtime_dependency('hashie', '~> 1.0.0')
   s.add_runtime_dependency('faraday', '~> 0.5.4')
   s.add_runtime_dependency('faraday_middleware', '~> 0.3.2')