diff --git a/.rubocop.yml b/.rubocop.yml
index 276cdc2..6cbf9a8 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,5 @@
-Style/MixinUsage:
-  Enabled: true
+AllCops:
+  TargetRubyVersion: 2.0
 
 Style/MultipleComparison:
   Enabled: false
diff --git a/pattern_patch.gemspec b/pattern_patch.gemspec
index be368fd..cc328f2 100644
--- a/pattern_patch.gemspec
+++ b/pattern_patch.gemspec
@@ -15,6 +15,8 @@ Gem::Specification.new do |spec|
   spec.homepage    = 'http://github.com/jdee/pattern_patch'
   spec.license     = 'MIT'
 
+  spec.required_ruby_version = '>= 2.0.0'
+
   spec.add_dependency 'activesupport'
 
   spec.add_development_dependency 'bundler'
@@ -23,7 +25,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rspec'
   spec.add_development_dependency 'rspec-simplecov'
   spec.add_development_dependency 'rspec_junit_formatter'
-  spec.add_development_dependency 'rubocop', '0.52.0'
+  spec.add_development_dependency 'rubocop', '0.50.0'
   spec.add_development_dependency 'simplecov'
   spec.add_development_dependency 'yard'
 end