diff --git a/.rubocop.yml b/.rubocop.yml
index ccceea45963969d06e4e964826e5576dbe8674eb..3fb2f2df5929759ca9436ebe99523d9e8ef6595b 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -770,7 +770,7 @@ Lint/DefEndAlignment:
 
 # Check for deprecated class method calls.
 Lint/DeprecatedClassMethods:
-  Enabled: false
+  Enabled: true
 
 # Check for duplicate method definitions.
 Lint/DuplicateMethods:
diff --git a/app/models/ci/build.rb b/app/models/ci/build.rb
index 4a3f92ad34aff229aea60fc8ea3fffadd3f71835..92327bdb08df149111f5aecf00274d991999e936 100644
--- a/app/models/ci/build.rb
+++ b/app/models/ci/build.rb
@@ -205,7 +205,7 @@ module Ci
     end
 
     def recreate_trace_dir
-      unless Dir.exists?(dir_to_trace)
+      unless Dir.exist?(dir_to_trace)
         FileUtils.mkdir_p(dir_to_trace)
       end
     end
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index 5460935366c3221f2aaf778545eb4190792b7304..5c5e6007aa0a746355ecf98b1e80d4e88a67f7d1 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -514,7 +514,7 @@ class MergeRequest < ActiveRecord::Base
   end
 
   def ref_is_fetched?
-    File.exists?(File.join(project.repository.path_to_repo, ref_path))
+    File.exist?(File.join(project.repository.path_to_repo, ref_path))
   end
 
   def ensure_ref_fetched
diff --git a/config/boot.rb b/config/boot.rb
index 4489e58688ca642d8e0e9489f6896f49f9b89da6..f2830ae3166dc7fc2849feff72258dccca1e5f97 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -3,4 +3,4 @@ require 'rubygems'
 # Set up gems listed in the Gemfile.
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
 
-require 'bundler/setup' if File.exists?(ENV['BUNDLE_GEMFILE'])
+require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
diff --git a/config/initializers/carrierwave.rb b/config/initializers/carrierwave.rb
index df28d30d750946bf32d3d4e5ae078bc7e3919ab0..0d278717d6ed9f528317127147aed64f46395f26 100644
--- a/config/initializers/carrierwave.rb
+++ b/config/initializers/carrierwave.rb
@@ -2,7 +2,7 @@ CarrierWave::SanitizedFile.sanitize_regexp = /[^[:word:]\.\-\+]/
 
 aws_file = Rails.root.join('config', 'aws.yml')
 
-if File.exists?(aws_file)
+if File.exist?(aws_file)
   AWS_CONFIG = YAML.load(File.read(aws_file))[Rails.env]
 
   CarrierWave.configure do |config|
diff --git a/lib/gitlab/backend/shell.rb b/lib/gitlab/backend/shell.rb
index 132f9cd1966ba9ed0929237041d1729322b7da6b..3e3986d63827811c894e741869c09f1fadb64da1 100644
--- a/lib/gitlab/backend/shell.rb
+++ b/lib/gitlab/backend/shell.rb
@@ -180,7 +180,7 @@ module Gitlab
     #   exists?('gitlab/cookies.git')
     #
     def exists?(dir_name)
-      File.exists?(full_path(dir_name))
+      File.exist?(full_path(dir_name))
     end
 
     protected
diff --git a/lib/gitlab/redis.rb b/lib/gitlab/redis.rb
index 5c352c96de522a57f7fe819cd67eadab89f08d60..f7db7a6391c051403a4a14351198262cc97a0a00 100644
--- a/lib/gitlab/redis.rb
+++ b/lib/gitlab/redis.rb
@@ -42,7 +42,7 @@ module Gitlab
       config_file = File.expand_path('../../../config/resque.yml', __FILE__)
   
       @url = "redis://localhost:6379"
-      if File.exists?(config_file)
+      if File.exist?(config_file)
         @url =YAML.load_file(config_file)[rails_env]
       end
     end
diff --git a/spec/config/mail_room_spec.rb b/spec/config/mail_room_spec.rb
index 462afb24f082a37d9eecf68bb174191e850eed2f..6fad7e2b9e7700b493f01f4b87d29c5c62b89d73 100644
--- a/spec/config/mail_room_spec.rb
+++ b/spec/config/mail_room_spec.rb
@@ -43,7 +43,7 @@ describe "mail_room.yml" do
       redis_config_file = Rails.root.join('config', 'resque.yml')
 
       redis_url =
-        if File.exists?(redis_config_file)
+        if File.exist?(redis_config_file)
           YAML.load_file(redis_config_file)[Rails.env]
         else
           "redis://localhost:6379"
diff --git a/spec/services/projects/create_service_spec.rb b/spec/services/projects/create_service_spec.rb
index e43903dbd3cefb7e068d2c11d42618c786858bbf..fd1143594672e541dbab0faa258ca548047671b7 100644
--- a/spec/services/projects/create_service_spec.rb
+++ b/spec/services/projects/create_service_spec.rb
@@ -64,7 +64,7 @@ describe Projects::CreateService, services: true do
           @path = ProjectWiki.new(@project, @user).send(:path_to_repo)
         end
 
-        it { expect(File.exists?(@path)).to be_truthy }
+        it { expect(File.exist?(@path)).to be_truthy }
       end
 
       context 'wiki_enabled false does not create wiki repository directory' do
@@ -74,7 +74,7 @@ describe Projects::CreateService, services: true do
           @path = ProjectWiki.new(@project, @user).send(:path_to_repo)
         end
 
-        it { expect(File.exists?(@path)).to be_falsey }
+        it { expect(File.exist?(@path)).to be_falsey }
       end
     end
 
diff --git a/spec/services/projects/destroy_service_spec.rb b/spec/services/projects/destroy_service_spec.rb
index 1ec2707771730ef4f31b54dfeca9f52a55675942..a5cb6f382e4931aff0cead42c2af595693facab6 100644
--- a/spec/services/projects/destroy_service_spec.rb
+++ b/spec/services/projects/destroy_service_spec.rb
@@ -13,8 +13,8 @@ describe Projects::DestroyService, services: true do
     end
 
     it { expect(Project.all).not_to include(project) }
-    it { expect(Dir.exists?(path)).to be_falsey }
-    it { expect(Dir.exists?(remove_path)).to be_falsey }
+    it { expect(Dir.exist?(path)).to be_falsey }
+    it { expect(Dir.exist?(remove_path)).to be_falsey }
   end
 
   context 'Sidekiq fake' do
@@ -24,8 +24,8 @@ describe Projects::DestroyService, services: true do
     end
 
     it { expect(Project.all).not_to include(project) }
-    it { expect(Dir.exists?(path)).to be_falsey }
-    it { expect(Dir.exists?(remove_path)).to be_truthy }
+    it { expect(Dir.exist?(path)).to be_falsey }
+    it { expect(Dir.exist?(remove_path)).to be_truthy }
   end
 
   def destroy_project(project, user, params)