diff --git a/.travis.yml b/.travis.yml
index ef952b31..784d4b5c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -36,7 +36,7 @@ env:
 jobs:
   include:
   - name: Rubocop Lint
-    script: gem install perx-rubocop && rubocop
+    script: gem install rubocop
 
   allow_failures:
     - rvm: ruby-head
diff --git a/Gemfile b/Gemfile
index fa74281e..0949319d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-source 'https://my.diffend.io/protect/gems'
+source 'http://rubygems.org'
 
 gemspec
 
diff --git a/gemfiles/rails_5_0.gemfile b/gemfiles/rails_5_0.gemfile
index e963b5b3..37dc042b 100644
--- a/gemfiles/rails_5_0.gemfile
+++ b/gemfiles/rails_5_0.gemfile
@@ -2,8 +2,8 @@
 
 source "http://rubygems.org"
 
-gem "perx-rubocop", "~> 0.0.3"
 gem "rails", "~> 5.0.0"
+gem "rubocop"
 
 group :local do
   gem "guard-rspec", "~> 4.2"
diff --git a/gemfiles/rails_5_1.gemfile b/gemfiles/rails_5_1.gemfile
index 8785b959..59af05f8 100644
--- a/gemfiles/rails_5_1.gemfile
+++ b/gemfiles/rails_5_1.gemfile
@@ -2,8 +2,8 @@
 
 source "http://rubygems.org"
 
-gem "perx-rubocop", "~> 0.0.3"
 gem "rails", "~> 5.1.0"
+gem "rubocop"
 
 group :local do
   gem "guard-rspec", "~> 4.2"
diff --git a/gemfiles/rails_5_2.gemfile b/gemfiles/rails_5_2.gemfile
index 1afc645b..18d8952a 100644
--- a/gemfiles/rails_5_2.gemfile
+++ b/gemfiles/rails_5_2.gemfile
@@ -2,8 +2,8 @@
 
 source "http://rubygems.org"
 
-gem "perx-rubocop", "~> 0.0.3"
 gem "rails", "~> 5.2.0"
+gem "rubocop"
 
 group :local do
   gem "guard-rspec", "~> 4.2"
diff --git a/gemfiles/rails_6_0.gemfile b/gemfiles/rails_6_0.gemfile
index 6c3d3968..6d23e4aa 100644
--- a/gemfiles/rails_6_0.gemfile
+++ b/gemfiles/rails_6_0.gemfile
@@ -2,8 +2,8 @@
 
 source "http://rubygems.org"
 
-gem "perx-rubocop", "~> 0.0.3"
 gem "rails", "~> 6.0.0"
+gem "rubocop"
 
 group :local do
   gem "guard-rspec", "~> 4.2"
diff --git a/gemfiles/rails_master.gemfile b/gemfiles/rails_master.gemfile
index f2add08a..82ad9191 100644
--- a/gemfiles/rails_master.gemfile
+++ b/gemfiles/rails_master.gemfile
@@ -2,8 +2,8 @@
 
 source "http://rubygems.org"
 
-gem "perx-rubocop", "~> 0.0.3"
 gem "rails", git: "https://github.com/rails/rails.git"
+gem "rubocop"
 
 group :local do
   gem "guard-rspec", "~> 4.2"