diff --git a/.rubocop.yml b/.rubocop.yml
index 3930505..985a27e 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,6 +1,9 @@
 AllCops:
   NewCops: enable
 
+Gemspec/RequiredRubyVersion:
+  Enabled: false
+
 Layout/AccessModifierIndentation:
   EnforcedStyle: outdent
 
@@ -11,8 +14,11 @@ Layout/LineLength:
 Layout/SpaceInsideHashLiteralBraces:
   EnforcedStyle: no_space
 
+Lint/MissingSuper:
+  Enabled: false
+
 Metrics/AbcSize:
-  Max: 17
+  Max: 18
 
 Metrics/BlockLength:
   Exclude:
@@ -52,6 +58,9 @@ Style/DoubleNegation:
 Style/ExpandPathArguments:
   Enabled: false
 
+Style/FrozenStringLiteralComment:
+  Enabled: false
+
 Style/HashSyntax:
   EnforcedStyle: hash_rockets
 
diff --git a/Gemfile b/Gemfile
index 94bd336..75f41f6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 source "https://rubygems.org"
 
 gem "rake", "~> 12.0"
diff --git a/Rakefile b/Rakefile
index 7097e8d..fd5db1e 100755
--- a/Rakefile
+++ b/Rakefile
@@ -1,5 +1,4 @@
 #!/usr/bin/env rake
-# frozen_string_literal: true
 
 require "bundler/gem_tasks"
 require "rspec/core/rake_task"
diff --git a/lib/omniauth-oauth2.rb b/lib/omniauth-oauth2.rb
index 48d302a..9986eca 100644
--- a/lib/omniauth-oauth2.rb
+++ b/lib/omniauth-oauth2.rb
@@ -1,4 +1,2 @@
-# frozen_string_literal: true
-
 require "omniauth-oauth2/version"
 require "omniauth/strategies/oauth2"
diff --git a/lib/omniauth-oauth2/version.rb b/lib/omniauth-oauth2/version.rb
index b8d6e73..c2c7281 100644
--- a/lib/omniauth-oauth2/version.rb
+++ b/lib/omniauth-oauth2/version.rb
@@ -1,7 +1,5 @@
-# frozen_string_literal: true
-
 module OmniAuth
   module OAuth2
-    VERSION = "1.6.0"
+    VERSION = "1.6.0".freeze
   end
 end
diff --git a/lib/omniauth/strategies/oauth2.rb b/lib/omniauth/strategies/oauth2.rb
index b69e6eb..d47137a 100644
--- a/lib/omniauth/strategies/oauth2.rb
+++ b/lib/omniauth/strategies/oauth2.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require "oauth2"
 require "omniauth"
 require "securerandom"
diff --git a/omniauth-oauth2.gemspec b/omniauth-oauth2.gemspec
index f443431..20abb26 100644
--- a/omniauth-oauth2.gemspec
+++ b/omniauth-oauth2.gemspec
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 lib = File.expand_path("../lib", __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require "omniauth-oauth2/version"
diff --git a/spec/helper.rb b/spec/helper.rb
index 561e680..280be5f 100644
--- a/spec/helper.rb
+++ b/spec/helper.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 $LOAD_PATH.unshift File.expand_path("..", __FILE__)
 $LOAD_PATH.unshift File.expand_path("../../lib", __FILE__)
 
diff --git a/spec/omniauth/strategies/oauth2_spec.rb b/spec/omniauth/strategies/oauth2_spec.rb
index f3c7d51..3b988f8 100644
--- a/spec/omniauth/strategies/oauth2_spec.rb
+++ b/spec/omniauth/strategies/oauth2_spec.rb
@@ -1,5 +1,3 @@
-# frozen_string_literal: true
-
 require "helper"
 
 describe OmniAuth::Strategies::OAuth2 do