diff --git a/.rubocop.yml b/.rubocop.yml
index 14f8e4a..33f69b6 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -2,7 +2,7 @@ require:
   - rubocop-rspec
 
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 2.4
 
 # Offense count: 1
 # Configuration parameters: CountComments, ExcludedMethods.
diff --git a/lib/rubocop/cop/sequel/concurrent_index.rb b/lib/rubocop/cop/sequel/concurrent_index.rb
index 59e0bbb..0a746c1 100644
--- a/lib/rubocop/cop/sequel/concurrent_index.rb
+++ b/lib/rubocop/cop/sequel/concurrent_index.rb
@@ -13,9 +13,7 @@ class ConcurrentIndex < Cop
 
         def on_send(node)
           indexes?(node) do |args|
-            if offensive?(args)
-              add_offense(node, location: :selector, message: MSG)
-            end
+            add_offense(node, location: :selector, message: MSG) if offensive?(args)
           end
         end
 
diff --git a/rubocop-sequel.gemspec b/rubocop-sequel.gemspec
index b2a47b5..42f575c 100644
--- a/rubocop-sequel.gemspec
+++ b/rubocop-sequel.gemspec
@@ -13,14 +13,16 @@ Gem::Specification.new do |gem|
   gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.name          = 'rubocop-sequel'
   gem.require_paths = ['lib']
-  gem.version       = '0.0.6'
+  gem.version       = '0.1.0'
 
-  gem.add_runtime_dependency 'rubocop', '~> 0.55', '>= 0.55'
+  gem.required_ruby_version = '~> 2.4'
 
-  gem.add_development_dependency 'rake', '~> 12.3.0', '>= 12.0.0'
-  gem.add_development_dependency 'rspec', '~> 3.7', '>= 3.7.0'
-  gem.add_development_dependency 'rubocop-rspec', '~> 1.25.0', '>= 1.25.0'
-  gem.add_development_dependency 'sequel', '~> 4.49', '>= 4.49.0'
+  gem.add_runtime_dependency 'rubocop', '~> 1.0'
+
+  gem.add_development_dependency 'rake', '~> 12.3.0'
+  gem.add_development_dependency 'rspec', '~> 3.7'
+  gem.add_development_dependency 'rubocop-rspec', '~> 2.0'
+  gem.add_development_dependency 'sequel', '~> 4.49'
   gem.add_development_dependency 'simplecov', '~> 0.16'
   gem.add_development_dependency 'sqlite3', '~> 1.3', '>= 1.3.12'
 end