diff --git a/.rubocop.yml b/.rubocop.yml
index 9579c43..399d269 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,10 @@
 inherit_from: .rubocop_todo.yml
 
+AllCops:
+  Exclude:
+    - 'vendor/**/*'
+    - 'gemfiles/**/*'
+
 Metrics/LineLength:
   Enabled: false
 
diff --git a/Gemfile b/Gemfile
index 9ff95e2..37ee7f6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 source "https://rubygems.org"
 
 gemspec
diff --git a/Rakefile b/Rakefile
index b5dcc06..d66a089 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require "bundler"
 require "bundler/gem_tasks"
 require "rubocop/rake_task"
diff --git a/github_changelog_generator.gemspec b/github_changelog_generator.gemspec
index db2348d..d9f2074 100644
--- a/github_changelog_generator.gemspec
+++ b/github_changelog_generator.gemspec
@@ -1,4 +1,5 @@
 # coding: utf-8
+# frozen_string_literal: true
 lib = File.expand_path("../lib", __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require "github_changelog_generator/version"
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 2edef57..2137e01 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # Author:: Enrico Stahn <mail@enricostahn.com>
 #
diff --git a/spec/unit/fetcher_spec.rb b/spec/unit/fetcher_spec.rb
index bba0c19..512895c 100644
--- a/spec/unit/fetcher_spec.rb
+++ b/spec/unit/fetcher_spec.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 VALID_TOKEN = "0123456789abcdef"
 INVALID_TOKEN = "0000000000000000"
 
diff --git a/spec/unit/generator/generator_processor_spec.rb b/spec/unit/generator/generator_processor_spec.rb
index 71f37c4..b636c2d 100644
--- a/spec/unit/generator/generator_processor_spec.rb
+++ b/spec/unit/generator/generator_processor_spec.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 module GitHubChangelogGenerator
   describe Generator do
     context "#exclude_issues_by_labels" do
diff --git a/spec/unit/generator/generator_tags_spec.rb b/spec/unit/generator/generator_tags_spec.rb
index 57fb8ba..86cdf70 100644
--- a/spec/unit/generator/generator_tags_spec.rb
+++ b/spec/unit/generator/generator_tags_spec.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 describe GitHubChangelogGenerator::Generator do
   def tag_mash_with_name(tag)
     Hashie::Mash.new.tap { |mash_tag| mash_tag.name = tag }
diff --git a/spec/unit/parse_file_spec.rb b/spec/unit/parse_file_spec.rb
index ad26aee..3ccb992 100644
--- a/spec/unit/parse_file_spec.rb
+++ b/spec/unit/parse_file_spec.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 describe GitHubChangelogGenerator::ParserFile do
   describe ".github_changelog_generator" do
     let(:options) { {} }
diff --git a/spec/unit/parser_spec.rb b/spec/unit/parser_spec.rb
index 84200b2..6ba9ef1 100644
--- a/spec/unit/parser_spec.rb
+++ b/spec/unit/parser_spec.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 describe GitHubChangelogGenerator::Parser do
   describe ".user_project_from_remote" do
     context "when remote is type 1" do
diff --git a/spec/unit/reader_spec.rb b/spec/unit/reader_spec.rb
index f5a2ef9..2bc21e8 100644
--- a/spec/unit/reader_spec.rb
+++ b/spec/unit/reader_spec.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # Author:: Enrico Stahn <mail@enricostahn.com>
 #