diff --git a/openvpn-status-web.gemspec b/openvpn-status-web.gemspec
index d61d7e5..950d723 100644
--- a/openvpn-status-web.gemspec
+++ b/openvpn-status-web.gemspec
@@ -37,6 +37,6 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'rack-test'
   s.add_development_dependency 'rake'
   s.add_development_dependency 'rspec'
-  s.add_development_dependency 'rubocop', '~> 1.4.1'
+  s.add_development_dependency 'rubocop', '~> 1.5.1'
   # s.add_development_dependency 'solargraph', ' ~> 0.39.0'
 end