diff --git a/openvpn-status-web.gemspec b/openvpn-status-web.gemspec
index e084782..36fba10 100644
--- a/openvpn-status-web.gemspec
+++ b/openvpn-status-web.gemspec
@@ -36,6 +36,6 @@ 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', '~> 0.90.0'
+  s.add_development_dependency 'rubocop', '~> 0.91.0'
   s.add_development_dependency 'solargraph'
 end