diff --git a/Gemfile b/Gemfile
index 922ef96..13a9d45 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,11 +8,11 @@ gem 'mongoid', '>= 2.0'
 # Include everything needed to run rake, tests, features, etc.
 group :development do
   gem 'bundler'
+  gem 'database_cleaner', '>= 0.8.0'
   gem 'jeweler', '~> 2.1.1'
-  gem 'rake'
   gem 'rack', '~> 1.6.4'
+  gem 'rake'
   gem 'rdoc'
   gem 'rspec', '>= 2.0.0'
   gem 'simplecov', '>= 0.4.0', require: false
-  gem 'database_cleaner', '>= 0.8.0'
 end
diff --git a/Rakefile b/Rakefile
index 807e40b..836f2d8 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,5 +1,3 @@
-# encoding: utf-8
-
 require 'rubygems'
 require 'rake'
 require 'bundler'
@@ -8,21 +6,21 @@ Bundler::GemHelper.install_tasks
 begin
   Bundler.setup(:default, :development)
 rescue Bundler::BundlerError => e
-  $stderr.puts e.message
-  $stderr.puts "Run `bundle install` to install missing gems"
+  warn e.message
+  warn 'Run `bundle install` to install missing gems'
   exit e.status_code
 end
 
 require 'jeweler'
 Jeweler::Tasks.new do |gem|
   # gem is a Gem::Specification... see http://docs.rubygems.org/read/chapter/20 for more options
-  gem.name = "mongoid_auto_increment"
-  gem.homepage = "http://github.com/proton/mongoid_auto_increment"
-  gem.license = "MIT"
-  gem.summary = %q{Auto-incrementing fields for Mongoid documents}
-  gem.description = %q{Add SQL like auto-incrementing fields to your Mongoid documents.}
-  gem.email = "psavichev@gmail.com"
-  gem.authors = ["Peter Savichev (proton)"]
+  gem.name = 'mongoid_auto_increment'
+  gem.homepage = 'http://github.com/proton/mongoid_auto_increment'
+  gem.license = 'MIT'
+  gem.summary = 'Auto-incrementing fields for Mongoid documents'
+  gem.description = 'Add SQL like auto-incrementing fields to your Mongoid documents.'
+  gem.email = 'psavichev@gmail.com'
+  gem.authors = ['Peter Savichev (proton)']
   # dependencies defined in Gemfile
 end
 Jeweler::RubygemsDotOrgTasks.new
@@ -33,11 +31,11 @@ RSpec::Core::RakeTask.new(:spec) do |spec|
   spec.pattern = 'spec/**/*_spec.rb'
 end
 
-task :default => :spec
+task default: :spec
 
 require 'rdoc/task'
 RDoc::Task.new do |rdoc|
-  version = File.exist?('VERSION') ? File.read('VERSION') : ""
+  version = File.exist?('VERSION') ? File.read('VERSION') : ''
 
   rdoc.rdoc_dir = 'rdoc'
   rdoc.title = "mongoid_auto_increment #{version}"
@@ -45,15 +43,15 @@ RDoc::Task.new do |rdoc|
   rdoc.rdoc_files.include('lib/**/*.rb')
 end
 
-desc "Build gem"
+desc 'Build gem'
 task :build do
-	puts "Regenerating gemspec"
-  system "rake gemspec"
-	puts "Building"
-  system "gem build mongoid_auto_increment.gemspec"
+  puts 'Regenerating gemspec'
+  system 'rake gemspec'
+  puts 'Building'
+  system 'gem build mongoid_auto_increment.gemspec'
 end
 
-desc "Release gem"
-task :release => :build do
-	version = File.exist?('VERSION') ? File.read('VERSION') : ""
+desc 'Release gem'
+task release: :build do
+  version = File.exist?('VERSION') ? File.read('VERSION') : ''
 end
diff --git a/lib/mongoid_auto_increment.rb b/lib/mongoid_auto_increment.rb
index 3a5684c..848356b 100644
--- a/lib/mongoid_auto_increment.rb
+++ b/lib/mongoid_auto_increment.rb
@@ -4,8 +4,8 @@ module MongoidAutoIncrement
   extend ActiveSupport::Concern
 
   module ClassMethods
-    def auto_increment(name, options={})
-      field name, :type => Integer
+    def auto_increment(name, options = {})
+      field name, type: Integer
 
       unless defined? @@incrementor
         @@incrementor = MongoidAutoIncrement::Incrementor.new
diff --git a/lib/mongoid_auto_increment/incrementor.rb b/lib/mongoid_auto_increment/incrementor.rb
index c37f3c9..4554ee0 100644
--- a/lib/mongoid_auto_increment/incrementor.rb
+++ b/lib/mongoid_auto_increment/incrementor.rb
@@ -1,5 +1,5 @@
 # This is a modified version of the code found on this blog post:
-#   http://ihswebdesign.com/blog/autoincrement-in-mongodb-with-ruby/
+# http://ihswebdesign.com/blog/autoincrement-in-mongodb-with-ruby/
 module MongoidAutoIncrement
   class Incrementor
     class Sequence
@@ -11,26 +11,26 @@ def initialize(sequence, collection_name, seed, step, scope)
         @step = step.to_i
       end
 
-       def inc
+      def inc
         if defined?(::Mongoid::VERSION) && ::Mongoid::VERSION >= '5'
           collection.find(query).find_one_and_update({ '$inc' => { number: @step } }, new: true, upsert: true, return_document: :after)['number']
         elsif defined?(::Mongoid::VERSION) && ::Mongoid::VERSION >= '3'
           collection.find(query).modify({ '$inc' => { number: @step } }, new: true, upsert: true)['number']
         else
           opts = {
-            "query"  => query,
-            "update" => {"$inc" => { "number" => @step }},
-            "new"    => true # return the modified document
+            'query'  => query,
+            'update' => { '$inc' => { 'number' => @step } },
+            'new'    => true # return the modified document
           }
-          collection.find_and_modify(opts)["number"]
+          collection.find_and_modify(opts)['number']
         end
-       end
+      end
 
       def current
         if defined?(::Mongoid::VERSION) && ::Mongoid::VERSION >= '3'
-          collection.find(query).one["number"]
+          collection.find(query).one['number']
         else
-          collection.find_one(query)["number"]
+          collection.find_one(query)['number']
         end
       end
 
@@ -42,9 +42,9 @@ def exists?
 
       def create(number)
         if ::Mongoid::VERSION >= '5'
-          collection.insert_one(query.merge({ "number" => number }))
+          collection.insert_one(query.merge('number' => number))
         else
-          collection.insert(query.merge({ "number" => number }))
+          collection.insert(query.merge('number' => number))
         end
       end
 
@@ -59,15 +59,14 @@ def collection
       end
 
       def query
-        @scope.merge("seq_name" => @sequence)
+        @scope.merge('seq_name' => @sequence)
       end
     end
 
-    def initialize(options=nil)
-    end
+    def initialize(options = nil); end
 
     def inc(sequence, options, record)
-      collection = options[:collection] || "sequences"
+      collection = options[:collection] || 'sequences'
       seed = options[:seed].to_i
       step = options[:step] || 1
       scope = resolve_scope(record, options[:scope])
diff --git a/spec/models/invoice.rb b/spec/models/invoice.rb
index 6e371a0..66a8f9a 100644
--- a/spec/models/invoice.rb
+++ b/spec/models/invoice.rb
@@ -4,6 +4,5 @@ class Invoice
 
   field :name
 
-  auto_increment :num, :seed => 1000, :step => 5
+  auto_increment :num, seed: 1000, step: 5
 end
-
diff --git a/spec/models/order.rb b/spec/models/order.rb
index 78f007a..a289d46 100644
--- a/spec/models/order.rb
+++ b/spec/models/order.rb
@@ -4,5 +4,5 @@ class Order
 
   field :title
 
-  auto_increment :num, :seed => 1000
+  auto_increment :num, seed: 1000
 end
diff --git a/spec/models/post.rb b/spec/models/post.rb
index fdcb6c6..c92b9ca 100644
--- a/spec/models/post.rb
+++ b/spec/models/post.rb
@@ -4,7 +4,7 @@ class Post
 
   field :title
 
-  auto_increment :key, :seed => 500
+  auto_increment :key, seed: 500
   auto_increment :num
 
   embeds_many :comments
diff --git a/spec/mongoid_auto_increment_spec.rb b/spec/mongoid_auto_increment_spec.rb
index 85b4cc3..8bb0ca7 100644
--- a/spec/mongoid_auto_increment_spec.rb
+++ b/spec/mongoid_auto_increment_spec.rb
@@ -1,25 +1,24 @@
 require 'spec_helper'
 
 describe 'mongoid_auto_increment' do
-
   before(:each) do
-    @book1 = Book.create :name => 'The Rails Way'
-    @book2 = Book.create :name => 'The Ruby Programming Language '
-    @book3 = Book.create :name => 'Metaprogramming Ruby'
-    @order1 = Order.create :name => 'First Order'
-    @order2 = Order.create :name => 'Second Order'
-    @order3 = Order.create :name => 'Last Order'
-    @post1 = Post.create :name => 'First Post'
-    @post2 = Post.create :name => 'Second Post'
-    @post3 = Post.create :name => 'Last Post'
-    @comment1 = @post1.comments.create :name => 'First Comment'
-    @comment2 = @post1.comments.create :name => 'Second Comment'
-    @invoice1 = Invoice.create :name => 'First invoice'
-    @invoice2 = Invoice.create :name => 'Second invoice'
-    @invoice3 = Invoice.create :name => 'Third invoice'
-    @record1 = Record.create :name => 'First record'
-    @record2 = Record.create :name => 'Second record'
-    @record3 = Record.create :name => 'Third record'
+    @book1 = Book.create name: 'The Rails Way'
+    @book2 = Book.create name: 'The Ruby Programming Language '
+    @book3 = Book.create name: 'Metaprogramming Ruby'
+    @order1 = Order.create name: 'First Order'
+    @order2 = Order.create name: 'Second Order'
+    @order3 = Order.create name: 'Last Order'
+    @post1 = Post.create name: 'First Post'
+    @post2 = Post.create name: 'Second Post'
+    @post3 = Post.create name: 'Last Post'
+    @comment1 = @post1.comments.create name: 'First Comment'
+    @comment2 = @post1.comments.create name: 'Second Comment'
+    @invoice1 = Invoice.create name: 'First invoice'
+    @invoice2 = Invoice.create name: 'Second invoice'
+    @invoice3 = Invoice.create name: 'Third invoice'
+    @record1 = Record.create name: 'First record'
+    @record2 = Record.create name: 'Second record'
+    @record3 = Record.create name: 'Third record'
   end
 
   describe 'single auto-increment field' do
@@ -120,7 +119,7 @@ def collection
     end
 
     it 'should have a sequence name of "Record"' do
-      expect(collection.find(:seq_name => 'Record').first).not_to eq nil
+      expect(collection.find(seq_name: 'Record').first).not_to eq nil
     end
   end
 
@@ -137,8 +136,8 @@ def collection
       end
 
       it 'should increment each scope separately' do
-        3.times.each{ |n| @recipe1.ingredients.create(name: n + 1) }
-        9.times.each{ |n| @recipe2.ingredients.create(name: n + 1) }
+        3.times.each { |n| @recipe1.ingredients.create(name: n + 1) }
+        9.times.each { |n| @recipe2.ingredients.create(name: n + 1) }
         expect(Ingredient.find_by(recipe: @recipe2, name: 3).order).to eq 3
         expect(Ingredient.find_by(recipe: @recipe2, name: 9).order).to eq 9
       end
@@ -151,8 +150,8 @@ def collection
       end
 
       it 'should increment each scope separately' do
-        3.times.each{ |n| Recipe.create(chef: 'Jack', name: n + 1) }
-        9.times.each{ |n| Recipe.create(chef: 'Jill', name: n + 1) }
+        3.times.each { |n| Recipe.create(chef: 'Jack', name: n + 1) }
+        9.times.each { |n| Recipe.create(chef: 'Jill', name: n + 1) }
         expect(Recipe.find_by(chef: 'Jack', name: 3).rank).to eq 3
         expect(Recipe.find_by(chef: 'Jill', name: 9).rank).to eq 9
       end
@@ -171,9 +170,9 @@ def collection
       end
 
       it 'should increment each scope separately' do
-        2.times.each{ |n| Ingredient.create(recipe: @recipe1, type: 'greens', name: n + 1) }
-        3.times.each{ |n| Ingredient.create(recipe: @recipe1, type: 'meats', name: n + 1) }
-        5.times.each{ |n| Ingredient.create(recipe: @recipe2, type: 'greens', name: n + 1) }
+        2.times.each { |n| Ingredient.create(recipe: @recipe1, type: 'greens', name: n + 1) }
+        3.times.each { |n| Ingredient.create(recipe: @recipe1, type: 'meats', name: n + 1) }
+        5.times.each { |n| Ingredient.create(recipe: @recipe2, type: 'greens', name: n + 1) }
         expect(Ingredient.find_by(recipe: @recipe1, type: 'greens', name: 2).cost).to eq 2
         expect(Ingredient.find_by(recipe: @recipe1, type: 'meats', name: 3).cost).to eq 3
         expect(Ingredient.find_by(recipe: @recipe2, type: 'greens', name: 5).cost).to eq 5
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index b584f13..ffeedd7 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,13 +1,13 @@
 $LOAD_PATH.unshift(File.dirname(__FILE__))
-$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), "..", "lib"))
+$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
 
-MODELS = File.join(File.dirname(__FILE__), "models")
+MODELS = File.join(File.dirname(__FILE__), 'models')
 
-require "rubygems"
-require "mongoid"
-require "mongoid_auto_increment"
-require "database_cleaner"
-require "simplecov"
+require 'rubygems'
+require 'mongoid'
+require 'mongoid_auto_increment'
+require 'database_cleaner'
+require 'simplecov'
 
 SimpleCov.start
 
@@ -15,14 +15,14 @@
 
 if defined?(::Mongoid::VERSION) && ::Mongoid::VERSION > '3'
   Mongoid.configure do |config|
-    config.connect_to "mongoid_auto_increment_test"
+    config.connect_to 'mongoid_auto_increment_test'
   end
 else
-  Mongoid.config.master = Mongo::Connection.new.db("mongoid_auto_increment_test")
+  Mongoid.config.master = Mongo::Connection.new.db('mongoid_auto_increment_test')
 end
 Mongoid.logger = Logger.new($stdout)
 
-DatabaseCleaner.orm = "mongoid"
+DatabaseCleaner.orm = 'mongoid'
 
 RSpec.configure do |config|
   config.before(:all) do
@@ -36,4 +36,4 @@
   config.after(:each) do
     DatabaseCleaner.clean
   end
-end
\ No newline at end of file
+end