diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 00000000..4d7c0559
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,17 @@
+AllCops:
+  Exclude:
+    - vendor/**/*
+
+inherit_from: .rubocop_todo.yml
+
+Style/AndOr:
+  EnforcedStyle: conditionals
+
+Style/SignalException:
+  EnforcedStyle: only_raise
+
+Style/HashSyntax:
+  EnforcedStyle: hash_rockets
+
+Style/AlignHash:
+  EnforcedHashRocketStyle: table
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
new file mode 100644
index 00000000..8cb1fc82
--- /dev/null
+++ b/.rubocop_todo.yml
@@ -0,0 +1,87 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config`
+# on 2015-11-18 09:55:16 -0500 using RuboCop version 0.35.1.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
+# Offense count: 1
+# Configuration parameters: AllowSafeAssignment.
+Lint/AssignmentInCondition:
+  Exclude:
+    - 'spec/spec_helper.rb'
+
+# Offense count: 3
+Metrics/AbcSize:
+  Max: 24
+
+# Offense count: 4
+Metrics/CyclomaticComplexity:
+  Max: 9
+
+# Offense count: 106
+# Configuration parameters: AllowURI, URISchemes.
+Metrics/LineLength:
+  Max: 143
+
+# Offense count: 6
+# Configuration parameters: CountComments.
+Metrics/MethodLength:
+  Max: 20
+
+# Offense count: 4
+Metrics/PerceivedComplexity:
+  Max: 12
+
+# Offense count: 2
+Style/AccessorMethodName:
+  Exclude:
+    - 'lib/virtus/attribute/accessor.rb'
+    - 'lib/virtus/support/options.rb'
+
+# Offense count: 2
+Style/CaseEquality:
+  Exclude:
+    - 'lib/virtus.rb'
+    - 'lib/virtus/module_extensions.rb'
+
+# Offense count: 15
+# Configuration parameters: Exclude.
+Style/Documentation:
+  Exclude:
+    - 'spec/**/*'
+    - 'test/**/*'
+    - 'lib/virtus.rb'
+    - 'lib/virtus/attribute/lazy_default.rb'
+    - 'lib/virtus/class_inclusions.rb'
+    - 'lib/virtus/const_missing_extensions.rb'
+    - 'lib/virtus/extensions.rb'
+    - 'lib/virtus/instance_methods.rb'
+    - 'lib/virtus/model.rb'
+    - 'lib/virtus/value_object.rb'
+    - 'lib/virtus/version.rb'
+
+# Offense count: 3
+# Configuration parameters: MinBodyLength.
+Style/GuardClause:
+  Exclude:
+    - 'lib/virtus/class_methods.rb'
+    - 'lib/virtus/instance_methods.rb'
+    - 'lib/virtus/support/type_lookup.rb'
+
+# Offense count: 1
+Style/ModuleFunction:
+  Exclude:
+    - 'spec/shared/constants_helpers.rb'
+
+# Offense count: 1
+Style/MultilineBlockChain:
+  Exclude:
+    - 'lib/virtus/module_extensions.rb'
+
+# Offense count: 1
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, EnforcedStyleForEmptyBraces, SupportedStyles.
+Style/SpaceInsideHashLiteralBraces:
+  Enabled: false
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 463b0e72..3c4bf2dd 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -7,6 +7,7 @@ Virtus recently hit it's 1.0 release (2013-10-16). The focus now is on bug-fixes
 * Fork the project.
 * Make your feature addition or bug fix.
 * Add tests for it. This is important so I don't break it in a future version unintentionally.
+* Run `rubocop -a` to fix any Ruby style issues and re-run `rubocop --auto-gen-config` for any acceptable exceptions.
 * Commit, do not mess with Rakefile or version
   (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
 * Send me a pull request. Bonus points for topic branches.
diff --git a/Gemfile b/Gemfile
index d33512bc..5a2414b3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,14 +6,18 @@ gem 'bogus', '~> 0.1'
 gem 'inflecto', '~> 0.0.2'
 gem 'rspec', '~> 3.1'
 
-gem "codeclimate-test-reporter", group: :test, require: false
+group :development, :test do
+  gem 'rubocop', '0.35.1'
+end
+
+group :test do
+  gem 'codeclimate-test-reporter', :require => false
+end
 
 group :tools do
   gem 'guard'
   gem 'guard-rspec'
 
-  gem 'rubocop'
-
   platform :mri do
     gem 'mutant'
     gem 'mutant-rspec'
diff --git a/Guardfile b/Guardfile
index 79dc623d..1ea41763 100644
--- a/Guardfile
+++ b/Guardfile
@@ -1,5 +1,5 @@
-guard :rspec, spec_paths: 'spec/unit' do
-  #run all specs if configuration is modified
+guard :rspec, :spec_paths => 'spec/unit' do
+  # run all specs if configuration is modified
   watch('Guardfile')           { 'spec' }
   watch('Gemfile.lock')        { 'spec' }
   watch('spec/spec_helper.rb') { 'spec' }
diff --git a/Rakefile b/Rakefile
index 179aabe1..78a0af50 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,15 +1,11 @@
-require "rspec/core/rake_task"
+require 'rspec/core/rake_task'
 
 RSpec::Core::RakeTask.new(:spec)
-task default: [:spec]
+task :default => [:spec]
 
-begin
-  require "rubocop/rake_task"
+require 'rubocop/rake_task'
+Rake::Task[:default].enhance [:rubocop]
 
-  Rake::Task[:default].enhance [:rubocop]
-
-  RuboCop::RakeTask.new do |task|
-    task.options << "--display-cop-names"
-  end
-rescue LoadError
+RuboCop::RakeTask.new do |task|
+  task.options << '--display-cop-names'
 end
diff --git a/lib/virtus.rb b/lib/virtus.rb
index 1b83ab0b..f3e2b9bd 100644
--- a/lib/virtus.rb
+++ b/lib/virtus.rb
@@ -2,10 +2,9 @@
 
 # Base module which adds Attribute API to your classes
 module Virtus
-
   # Provides args for const_get and const_defined? to make them behave
   # consistently across different versions of ruby
-  EXTRA_CONST_ARGS = (RUBY_VERSION < '1.9' ? [] : [ false ]).freeze
+  EXTRA_CONST_ARGS = (RUBY_VERSION < '1.9' ? [] : [false]).freeze
 
   # Represents an undefined parameter used by auto-generated option methods
   Undefined = Object.new.freeze
@@ -14,7 +13,8 @@ class CoercionError < StandardError
     attr_reader :output, :attribute
 
     def initialize(output, attribute)
-      @output, @attribute = output, attribute
+      @output = output
+      @attribute = attribute
       super(build_message)
     end
 
@@ -120,7 +120,7 @@ def self.coerce
   # @return [Configuration]
   #
   # @api public
-  def self.config(&block)
+  def self.config
     yield configuration if block_given?
     configuration
   end
@@ -237,7 +237,6 @@ def self.finalize
   def self.warn(msg)
     Kernel.warn(msg)
   end
-
 end # module Virtus
 
 require 'descendants_tracker'
diff --git a/lib/virtus/attribute.rb b/lib/virtus/attribute.rb
index 0654d4d1..c8c7ddfc 100644
--- a/lib/virtus/attribute.rb
+++ b/lib/virtus/attribute.rb
@@ -1,5 +1,4 @@
 module Virtus
-
   # Attribute objects handle coercion and provide interface to hook into an
   # attribute set instance that's included into a class or object
   #
@@ -140,7 +139,7 @@ def value_coerced?(value)
     #
     # @api public
     def coercible?
-      kind_of?(Coercible)
+      is_a?(Coercible)
     end
 
     # Return if the attribute has lazy default value evaluation
@@ -157,7 +156,7 @@ def coercible?
     #
     # @api public
     def lazy?
-      kind_of?(LazyDefault)
+      is_a?(LazyDefault)
     end
 
     # Return if the attribute is in the strict coercion mode
@@ -174,7 +173,7 @@ def lazy?
     #
     # @api public
     def strict?
-      kind_of?(Strict)
+      is_a?(Strict)
     end
 
     # Return if the attribute is in the nullify blank coercion mode
@@ -191,7 +190,7 @@ def strict?
     #
     # @api public
     def nullify_blank?
-      kind_of?(NullifyBlank)
+      is_a?(NullifyBlank)
     end
 
     # Return if the attribute is accepts nil values as valid coercion output
@@ -239,7 +238,5 @@ def finalize
       freeze
       self
     end
-
   end # class Attribute
-
 end # module Virtus
diff --git a/lib/virtus/attribute/accessor.rb b/lib/virtus/attribute/accessor.rb
index 7a51f03d..8b628088 100644
--- a/lib/virtus/attribute/accessor.rb
+++ b/lib/virtus/attribute/accessor.rb
@@ -1,6 +1,5 @@
 module Virtus
   class Attribute
-
     # Accessor extension provides methods to read and write attributes
     #
     # @example
@@ -13,7 +12,6 @@ class Attribute
     #   attribute.get(object) # => 'jane@doe.com'
     #
     module Accessor
-
       # Return name of this accessor attribute
       #
       # @return [Symbol]
@@ -96,8 +94,6 @@ def public_reader?
       def public_writer?
         options[:writer] == :public
       end
-
     end # Accessor
-
   end # Attribute
 end # Virtus
diff --git a/lib/virtus/attribute/boolean.rb b/lib/virtus/attribute/boolean.rb
index c3b72efb..dbe3a4a2 100644
--- a/lib/virtus/attribute/boolean.rb
+++ b/lib/virtus/attribute/boolean.rb
@@ -1,6 +1,5 @@
 module Virtus
   class Attribute
-
     # Boolean attribute allows true or false values to be set
     # Additionally it adds boolean reader method, like "admin?"
     #
@@ -49,7 +48,6 @@ def define_accessor_methods(attribute_set)
         super
         attribute_set.define_reader_method(self, "#{name}?", options[:reader])
       end
-
     end # class Boolean
   end # class Attribute
 end # module Virtus
diff --git a/lib/virtus/attribute/builder.rb b/lib/virtus/attribute/builder.rb
index 9ac6faa5..683ab161 100644
--- a/lib/virtus/attribute/builder.rb
+++ b/lib/virtus/attribute/builder.rb
@@ -1,5 +1,4 @@
 module Virtus
-
   # Attribute placeholder used when type constant is passed as a string or symbol
   #
   # @private
@@ -8,7 +7,8 @@ class PendingAttribute
 
     # @api private
     def initialize(type, options)
-      @type, @options = type.to_s, options
+      @type = type.to_s
+      @options = options
       @name = options[:name]
     end
 
@@ -36,7 +36,6 @@ def determine_type
         Object.const_get(type)
       end
     end
-
   end # PendingAttribute
 
   # Extracts the actual type primitive from input type
@@ -64,13 +63,13 @@ def initialize_primitive
         if type.instance_of?(String) || type.instance_of?(Symbol)
           if !type.to_s.include?('::') && Object.const_defined?(type)
             Object.const_get(type)
-          elsif not Attribute::Builder.determine_type(type)
+          elsif !Attribute::Builder.determine_type(type)
             @pending = true
             type
           else
             type
           end
-        elsif not type.is_a?(Class)
+        elsif !type.is_a?(Class)
           type.class
         else
           type
@@ -79,7 +78,6 @@ def initialize_primitive
   end
 
   class Attribute
-
     # Builder is used to set up an attribute instance based on input type and options
     #
     # @private
@@ -181,8 +179,6 @@ def determine_visibility
         writer_visibility = options.fetch(:writer, default_accessor)
         options.update(:reader => reader_visibility, :writer => writer_visibility)
       end
-
     end # class Builder
-
   end # class Attribute
 end # module Virtus
diff --git a/lib/virtus/attribute/coercer.rb b/lib/virtus/attribute/coercer.rb
index a37fc0dd..46e7f03f 100644
--- a/lib/virtus/attribute/coercer.rb
+++ b/lib/virtus/attribute/coercer.rb
@@ -1,11 +1,9 @@
 module Virtus
   class Attribute
-
     # Coercer accessor wrapper
     #
     # @api private
     class Coercer < Virtus::Coercer
-
       # @api private
       attr_reader :method, :coercers
 
@@ -38,8 +36,6 @@ def call(value)
       def success?(primitive, value)
         coercers[primitive].coerced?(value)
       end
-
     end # class Coercer
-
   end # class Attribute
 end # module Virtus
diff --git a/lib/virtus/attribute/coercible.rb b/lib/virtus/attribute/coercible.rb
index 2b966d6e..950e11ed 100644
--- a/lib/virtus/attribute/coercible.rb
+++ b/lib/virtus/attribute/coercible.rb
@@ -1,10 +1,8 @@
 module Virtus
   class Attribute
-
     # Attribute extension providing coercion when setting an attribute value
     #
     module Coercible
-
       # Coerce value before setting
       #
       # @see Accessor#set
@@ -13,8 +11,6 @@ module Coercible
       def set(instance, value)
         super(instance, coerce(value))
       end
-
     end # Coercible
-
   end # Attribute
 end # Virtus
diff --git a/lib/virtus/attribute/collection.rb b/lib/virtus/attribute/collection.rb
index 1b3a20b6..27293e31 100644
--- a/lib/virtus/attribute/collection.rb
+++ b/lib/virtus/attribute/collection.rb
@@ -1,12 +1,11 @@
 module Virtus
   class Attribute
-
     # Collection attribute handles enumerable-like types
     #
     # Handles coercing members to the designated member type.
     #
     class Collection < Attribute
-      default Proc.new { |_, attribute| attribute.primitive.new }
+      default proc { |_, attribute| attribute.primitive.new }
 
       # @api private
       attr_reader :member_type
@@ -22,10 +21,10 @@ def self.infer(type, primitive)
           if EmbeddedValue.handles?(member) || pending?(member)
             Type.new(primitive, member)
           else
-            klass.new {
+            klass.new do
               primitive primitive
               member_type Axiom::Types.infer(member)
-            }
+            end
           end
         end
 
@@ -66,7 +65,7 @@ def self.build_type(definition)
 
       # @api private
       def self.merge_options!(type, options)
-        options[:member_type] ||= Attribute.build(type.member_type, strict: options[:strict])
+        options[:member_type] ||= Attribute.build(type.member_type, :strict => options[:strict])
       end
 
       # @api public
@@ -91,8 +90,6 @@ def finalize
       def finalized?
         super && member_type.finalized?
       end
-
     end # class Collection
-
   end # class Attribute
 end # module Virtus
diff --git a/lib/virtus/attribute/default_value.rb b/lib/virtus/attribute/default_value.rb
index eca7350f..3e4f5ff8 100644
--- a/lib/virtus/attribute/default_value.rb
+++ b/lib/virtus/attribute/default_value.rb
@@ -1,6 +1,5 @@
 module Virtus
   class Attribute
-
     # Class representing the default value option
     #
     # @api private
@@ -45,7 +44,6 @@ def initialize(value)
       def call(*)
         value
       end
-
     end # class DefaultValue
   end # class Attribute
 end # module Virtus
diff --git a/lib/virtus/attribute/default_value/from_callable.rb b/lib/virtus/attribute/default_value/from_callable.rb
index cd3f8f52..cbb54e52 100644
--- a/lib/virtus/attribute/default_value/from_callable.rb
+++ b/lib/virtus/attribute/default_value/from_callable.rb
@@ -1,12 +1,10 @@
 module Virtus
   class Attribute
     class DefaultValue
-
       # Represents default value evaluated via a callable object
       #
       # @api private
       class FromCallable < DefaultValue
-
         # Return if the class can handle the value
         #
         # @param [Object] value
@@ -28,7 +26,6 @@ def self.handle?(value)
         def call(*args)
           @value.call(*args)
         end
-
       end # class FromCallable
     end # class DefaultValue
   end # class Attribute
diff --git a/lib/virtus/attribute/default_value/from_clonable.rb b/lib/virtus/attribute/default_value/from_clonable.rb
index ffb6f177..1747a8f4 100644
--- a/lib/virtus/attribute/default_value/from_clonable.rb
+++ b/lib/virtus/attribute/default_value/from_clonable.rb
@@ -1,13 +1,12 @@
 module Virtus
   class Attribute
     class DefaultValue
-
       # Represents default value evaluated via a clonable object
       #
       # @api private
       class FromClonable < DefaultValue
         SINGLETON_CLASSES = [
-          ::NilClass, ::TrueClass, ::FalseClass, ::Numeric,  ::Symbol ].freeze
+          ::NilClass, ::TrueClass, ::FalseClass, ::Numeric, ::Symbol].freeze
 
         # Return if the class can handle the value
         #
@@ -17,7 +16,7 @@ class FromClonable < DefaultValue
         #
         # @api private
         def self.handle?(value)
-          SINGLETON_CLASSES.none? { |klass| value.kind_of?(klass) }
+          SINGLETON_CLASSES.none? { |klass| value.is_a?(klass) }
         end
 
         # Evaluates the value via value#clone
@@ -28,7 +27,6 @@ def self.handle?(value)
         def call(*)
           @value.clone
         end
-
       end # class FromClonable
     end # class DefaultValue
   end # class Attribute
diff --git a/lib/virtus/attribute/default_value/from_symbol.rb b/lib/virtus/attribute/default_value/from_symbol.rb
index ef0e7dcf..b48428c6 100644
--- a/lib/virtus/attribute/default_value/from_symbol.rb
+++ b/lib/virtus/attribute/default_value/from_symbol.rb
@@ -1,12 +1,10 @@
 module Virtus
   class Attribute
     class DefaultValue
-
       # Represents default value evaluated via a symbol
       #
       # @api private
       class FromSymbol < DefaultValue
-
         # Return if the class can handle the value
         #
         # @param [Object] value
@@ -28,7 +26,6 @@ def self.handle?(value)
         def call(instance, _)
           instance.respond_to?(@value, true) ? instance.send(@value) : @value
         end
-
       end # class FromSymbol
     end # class DefaultValue
   end # class Attribute
diff --git a/lib/virtus/attribute/embedded_value.rb b/lib/virtus/attribute/embedded_value.rb
index cca93799..d5bcc124 100644
--- a/lib/virtus/attribute/embedded_value.rb
+++ b/lib/virtus/attribute/embedded_value.rb
@@ -1,6 +1,5 @@
 module Virtus
   class Attribute
-
     # EmbeddedValue handles virtus-like objects, OpenStruct and Struct
     #
     class EmbeddedValue < Attribute
@@ -11,16 +10,14 @@ class EmbeddedValue < Attribute
       #
       # @private
       class FromStruct < Virtus::Coercer
-
         # @api public
         def call(input)
-          if input.kind_of?(primitive)
+          if input.is_a?(primitive)
             input
-          elsif not input.nil?
+          elsif !input.nil?
             primitive.new(*input)
           end
         end
-
       end # FromStruct
 
       # Builds OpenStruct-like instance with attributes passed to the constructor
@@ -28,16 +25,14 @@ def call(input)
       #
       # @private
       class FromOpenStruct < Virtus::Coercer
-
         # @api public
         def call(input)
-          if input.kind_of?(primitive)
+          if input.is_a?(primitive)
             input
-          elsif not input.nil?
+          elsif !input.nil?
             primitive.new(input)
           end
         end
-
       end # FromOpenStruct
 
       # @api private
@@ -60,8 +55,6 @@ def self.build_coercer(type, _options)
           FromStruct.new(type)
         end
       end
-
     end # class EmbeddedValue
-
   end # class Attribute
 end # module Virtus
diff --git a/lib/virtus/attribute/hash.rb b/lib/virtus/attribute/hash.rb
index 7979c8e0..9319c516 100644
--- a/lib/virtus/attribute/hash.rb
+++ b/lib/virtus/attribute/hash.rb
@@ -1,11 +1,10 @@
 module Virtus
   class Attribute
-
     # Handles attributes with Hash type
     #
     class Hash < Attribute
       primitive ::Hash
-      default   primitive.new
+      default primitive.new
 
       # @api private
       attr_reader :key_type, :value_type
@@ -49,12 +48,13 @@ def self.determine_type(type)
 
         # @api private
         def self.infer_key_and_value_types(type)
-          return {} unless type.kind_of?(::Hash)
+          return {} unless type.is_a?(::Hash)
 
           if type.size > 1
             raise ArgumentError, "more than one [key => value] pair in `#{type}`"
           else
-            key_type, value_type = type.keys.first, type.values.first
+            key_type = type.keys.first
+            value_type = type.values.first
 
             key_primitive =
               if key_type.is_a?(Class) && key_type < Attribute && key_type.primitive
@@ -70,7 +70,7 @@ def self.infer_key_and_value_types(type)
                 value_type
               end
 
-            { :key_type => key_primitive, :value_type => value_primitive}
+            { :key_type => key_primitive, :value_type => value_primitive }
           end
         end
 
@@ -92,7 +92,7 @@ def self.build_type(definition)
 
       # @api private
       def self.merge_options!(type, options)
-        options[:key_type]   ||= Attribute.build(type.key_type, :strict => options[:strict])
+        options[:key_type] ||= Attribute.build(type.key_type, :strict => options[:strict])
         options[:value_type] ||= Attribute.build(type.value_type, :strict => options[:strict])
       end
 
@@ -123,8 +123,6 @@ def finalize
       def finalized?
         super && key_type.finalized? && value_type.finalized?
       end
-
     end # class Hash
-
   end # class Attribute
 end # module Virtus
diff --git a/lib/virtus/attribute/lazy_default.rb b/lib/virtus/attribute/lazy_default.rb
index 6363640b..973e145b 100644
--- a/lib/virtus/attribute/lazy_default.rb
+++ b/lib/virtus/attribute/lazy_default.rb
@@ -1,8 +1,6 @@
 module Virtus
   class Attribute
-
     module LazyDefault
-
       # @api public
       def get(instance)
         if instance.instance_variable_defined?(instance_variable_name)
@@ -11,8 +9,6 @@ def get(instance)
           set_default_value(instance)
         end
       end
-
     end # LazyDefault
-
   end # Attribute
 end # Virtus
diff --git a/lib/virtus/attribute/nullify_blank.rb b/lib/virtus/attribute/nullify_blank.rb
index e43cf3b2..78c2ab46 100644
--- a/lib/virtus/attribute/nullify_blank.rb
+++ b/lib/virtus/attribute/nullify_blank.rb
@@ -1,10 +1,8 @@
 module Virtus
   class Attribute
-
     # Attribute extension which nullifies blank attributes when coercion failed
     #
     module NullifyBlank
-
       # @see [Attribute#coerce]
       #
       # @api public
@@ -17,8 +15,6 @@ def coerce(input)
           output
         end
       end
-
     end # NullifyBlank
-
   end # Attribute
 end # Virtus
diff --git a/lib/virtus/attribute/strict.rb b/lib/virtus/attribute/strict.rb
index 87fc40f6..762f02a5 100644
--- a/lib/virtus/attribute/strict.rb
+++ b/lib/virtus/attribute/strict.rb
@@ -1,10 +1,8 @@
 module Virtus
   class Attribute
-
     # Attribute extension which raises CoercionError when coercion failed
     #
     module Strict
-
       # @see [Attribute#coerce]
       #
       # @raises [CoercionError] when coercer failed
@@ -19,8 +17,6 @@ def coerce(*)
           raise CoercionError.new(output, self)
         end
       end
-
     end # Strict
-
   end # Attribute
 end # Virtus
diff --git a/lib/virtus/attribute_set.rb b/lib/virtus/attribute_set.rb
index 66055a84..be9565e8 100644
--- a/lib/virtus/attribute_set.rb
+++ b/lib/virtus/attribute_set.rb
@@ -1,5 +1,4 @@
 module Virtus
-
   # A set of Attribute objects
   class AttributeSet < Module
     include Enumerable
@@ -43,7 +42,7 @@ def initialize(parent = nil, attributes = [])
     # @api public
     def each
       return to_enum unless block_given?
-      @index.each { |name, attribute| yield attribute if name.kind_of?(Symbol) }
+      @index.each { |name, attribute| yield attribute if name.is_a?(Symbol) }
       self
     end
 
@@ -235,6 +234,5 @@ def merge_attributes(attributes)
     def update_index(name, attribute)
       @index[name] = @index[name.to_s.freeze] = attribute
     end
-
   end # class AttributeSet
 end # module Virtus
diff --git a/lib/virtus/builder.rb b/lib/virtus/builder.rb
index 8216414a..0cb230e8 100644
--- a/lib/virtus/builder.rb
+++ b/lib/virtus/builder.rb
@@ -1,5 +1,4 @@
 module Virtus
-
   # Class to build a Virtus module with it's own config
   #
   # This allows for individual Virtus modules to be included in
@@ -8,7 +7,6 @@ module Virtus
   #
   # @private
   class Builder
-
     # Return module
     #
     # @return [Module]
@@ -42,7 +40,8 @@ def self.pending
     #
     # @api private
     def initialize(conf, mod = Module.new)
-      @config, @mod = conf, mod
+      @config = conf
+      @mod = mod
       add_included_hook
       add_extended_hook
     end
@@ -89,7 +88,6 @@ def add_extended_hook
     def with_hook_context
       yield(HookContext.new(self, config))
     end
-
   end # class Builder
 
   # @private
@@ -98,7 +96,6 @@ class ModelBuilder < Builder
 
   # @private
   class ModuleBuilder < Builder
-
     private
 
     # @api private
@@ -112,12 +109,10 @@ def add_included_hook
         end
       end
     end
-
   end # ModuleBuilder
 
   # @private
   class ValueObjectBuilder < Builder
-
     # @api private
     def extensions
       super << ValueObject::AllowedWriterMethods << ValueObject::InstanceMethods
@@ -127,7 +122,5 @@ def extensions
     def options
       super.merge(:writer => :private)
     end
-
   end # ValueObjectBuilder
-
 end # module Virtus
diff --git a/lib/virtus/builder/hook_context.rb b/lib/virtus/builder/hook_context.rb
index 4166e3e0..ad704703 100644
--- a/lib/virtus/builder/hook_context.rb
+++ b/lib/virtus/builder/hook_context.rb
@@ -1,6 +1,5 @@
 module Virtus
   class Builder
-
     # Context used for building "included" and "extended" hooks
     #
     # @private
@@ -9,7 +8,8 @@ class HookContext
 
       # @api private
       def initialize(builder, config)
-        @builder, @config = builder, config
+        @builder = builder
+        @config = config
         initialize_attribute_method
       end
 
@@ -44,8 +44,6 @@ def initialize_attribute_method
           super(name, type, method_options.merge(options))
         end
       end
-
     end # HookContext
-
   end # Builder
 end # Virtus
diff --git a/lib/virtus/class_inclusions.rb b/lib/virtus/class_inclusions.rb
index aab1afd0..4c826e37 100644
--- a/lib/virtus/class_inclusions.rb
+++ b/lib/virtus/class_inclusions.rb
@@ -1,8 +1,6 @@
 module Virtus
-
   # Class-level extensions
   module ClassInclusions
-
     # Extends a descendant with class and instance methods
     #
     # @param [Class] descendant
@@ -21,7 +19,6 @@ def self.included(descendant)
     private_class_method :included
 
     module Methods
-
       # Return a list of allowed writer method names
       #
       # @return [Set]
@@ -41,8 +38,6 @@ def allowed_writer_methods
       def attribute_set
         self.class.attribute_set
       end
-
     end # Methods
-
   end # module ClassInclusions
 end # module Virtus
diff --git a/lib/virtus/class_methods.rb b/lib/virtus/class_methods.rb
index 7f5930a9..5b88ab92 100644
--- a/lib/virtus/class_methods.rb
+++ b/lib/virtus/class_methods.rb
@@ -1,5 +1,4 @@
 module Virtus
-
   # Class methods that are added when you include Virtus
   module ClassMethods
     include Extensions::Methods
@@ -85,6 +84,5 @@ def assert_valid_name(name)
         raise ArgumentError, "#{name.inspect} is not allowed as an attribute name"
       end
     end
-
   end # module ClassMethods
 end # module Virtus
diff --git a/lib/virtus/coercer.rb b/lib/virtus/coercer.rb
index 676d5537..2e399e94 100644
--- a/lib/virtus/coercer.rb
+++ b/lib/virtus/coercer.rb
@@ -1,5 +1,4 @@
 module Virtus
-
   # Abstract coercer class
   #
   class Coercer
@@ -21,7 +20,7 @@ def initialize(type)
     # @return [Object] coerced input
     #
     # @api public
-    def call(input)
+    def call(_input)
       NotImplementedError.new("#{self.class}#call must be implemented")
     end
 
@@ -33,9 +32,7 @@ def call(input)
     #
     # @api public
     def success?(primitive, input)
-      input.kind_of?(primitive)
+      input.is_a?(primitive)
     end
-
   end # Coercer
-
 end # Virtus
diff --git a/lib/virtus/configuration.rb b/lib/virtus/configuration.rb
index 7e91b300..74f62911 100644
--- a/lib/virtus/configuration.rb
+++ b/lib/virtus/configuration.rb
@@ -1,8 +1,6 @@
 module Virtus
-
   # A Configuration instance
   class Configuration
-
     # Access the finalize setting for this instance
     attr_accessor :finalize
 
@@ -29,7 +27,7 @@ class Configuration
     # @return [undefined]
     #
     # @api private
-    def initialize(options={})
+    def initialize(options = {})
       @finalize        = options.fetch(:finalize, true)
       @coerce          = options.fetch(:coerce, true)
       @strict          = options.fetch(:strict, false)
@@ -67,6 +65,5 @@ def to_h
         :required           => required,
         :configured_coercer => coercer }.freeze
     end
-
   end # class Configuration
 end # module Virtus
diff --git a/lib/virtus/const_missing_extensions.rb b/lib/virtus/const_missing_extensions.rb
index fe374525..c545e6c3 100644
--- a/lib/virtus/const_missing_extensions.rb
+++ b/lib/virtus/const_missing_extensions.rb
@@ -1,6 +1,5 @@
 module Virtus
   module ConstMissingExtensions
-
     # Hooks into const missing process to determine types of attributes
     #
     # @param [String] name
@@ -9,10 +8,9 @@ module ConstMissingExtensions
     #
     # @api private
     def const_missing(name)
-      Attribute::Builder.determine_type(name) or
-        Axiom::Types.const_defined?(name) && Axiom::Types.const_get(name) or
+      Attribute::Builder.determine_type(name) ||
+        Axiom::Types.const_defined?(name) && Axiom::Types.const_get(name) ||
         super
     end
-
   end
 end
diff --git a/lib/virtus/extensions.rb b/lib/virtus/extensions.rb
index 031fb8ca..5691e21e 100644
--- a/lib/virtus/extensions.rb
+++ b/lib/virtus/extensions.rb
@@ -1,9 +1,8 @@
 module Virtus
-
   # Extensions common for both classes and instances
   module Extensions
     WRITER_METHOD_REGEXP   = /=\z/.freeze
-    INVALID_WRITER_METHODS = %w[ == != === []= attributes= ].to_set.freeze
+    INVALID_WRITER_METHODS = %w( == != === []= attributes= ).to_set.freeze
     RESERVED_NAMES         = [:attributes].to_set.freeze
 
     # A hook called when an object is extended with Virtus
@@ -24,7 +23,6 @@ def self.extended(object)
     private_class_method :extended
 
     module Methods
-
       # @api private
       def self.extended(descendant)
         super
@@ -68,9 +66,9 @@ def attribute(name, type = nil, options = {})
       # @see Virtus.default_value
       #
       # @api public
-      def values(&block)
+      def values
         private :attributes= if instance_methods.include?(:attributes=)
-        yield
+        yield if block_given?
         include(::Equalizer.new(*attribute_set.map(&:name)))
       end
 
@@ -98,8 +96,6 @@ def allowed_writer_methods
       def attribute_set
         @attribute_set
       end
-
     end # Methods
-
   end # module Extensions
 end # module Virtus
diff --git a/lib/virtus/instance_methods.rb b/lib/virtus/instance_methods.rb
index 4448bf66..df433ba6 100644
--- a/lib/virtus/instance_methods.rb
+++ b/lib/virtus/instance_methods.rb
@@ -1,10 +1,7 @@
 module Virtus
-
   # Instance methods that are added when you include Virtus
   module InstanceMethods
-
     module Constructor
-
       # Set attributes during initialization of an object
       #
       # @param [#to_hash] attributes
@@ -17,11 +14,9 @@ def initialize(attributes = nil)
         attribute_set.set(self, attributes) if attributes
         set_default_attributes
       end
-
     end # Constructor
 
     module MassAssignment
-
       # Returns a hash of all publicly accessible attributes
       #
       # @example
@@ -70,7 +65,6 @@ def attributes
       def attributes=(attributes)
         attribute_set.set(self, attributes)
       end
-
     end # MassAssignment
 
     # Returns a value of the attribute with the given name
@@ -213,6 +207,5 @@ def assert_valid_name(name)
         raise ArgumentError, "#{name.inspect} is not allowed as an attribute name"
       end
     end
-
   end # module InstanceMethods
 end # module Virtus
diff --git a/lib/virtus/model.rb b/lib/virtus/model.rb
index 0eaf06a9..c3f1ac87 100644
--- a/lib/virtus/model.rb
+++ b/lib/virtus/model.rb
@@ -1,7 +1,5 @@
 module Virtus
-
   module Model
-
     # @api private
     def self.included(descendant)
       super
@@ -15,7 +13,6 @@ def self.extended(descendant)
     end
 
     module Core
-
       # @api private
       def self.included(descendant)
         super
@@ -32,22 +29,18 @@ def self.extended(descendant)
         descendant.extend(InstanceMethods)
       end
       private_class_method :extended
-
     end # Core
 
     module Constructor
-
       # @api private
       def self.included(descendant)
         super
         descendant.send(:include, InstanceMethods::Constructor)
       end
       private_class_method :included
-
     end # Constructor
 
     module MassAssignment
-
       # @api private
       def self.included(descendant)
         super
@@ -61,8 +54,6 @@ def self.extended(descendant)
         descendant.extend(InstanceMethods::MassAssignment)
       end
       private_class_method :extended
-
     end # MassAssignment
-
   end # Model
 end # Virtus
diff --git a/lib/virtus/module_extensions.rb b/lib/virtus/module_extensions.rb
index ece4f2bf..bf4d81f2 100644
--- a/lib/virtus/module_extensions.rb
+++ b/lib/virtus/module_extensions.rb
@@ -1,5 +1,4 @@
 module Virtus
-
   # Virtus module that can define attributes for later inclusion
   #
   # @private
@@ -83,6 +82,5 @@ def define_attributes(object)
         object.attribute(*attribute_args)
       end
     end
-
   end # module ModuleExtensions
 end # module Virtus
diff --git a/lib/virtus/support/equalizer.rb b/lib/virtus/support/equalizer.rb
index 9784853f..bd2f0349 100644
--- a/lib/virtus/support/equalizer.rb
+++ b/lib/virtus/support/equalizer.rb
@@ -1,8 +1,6 @@
 module Virtus
-
   # Define equality, equivalence and inspection methods
   class Equalizer < Module
-
     # Initialize an Equalizer with the given keys
     #
     # Will use the keys with which it is initialized to define #cmp?,
@@ -32,7 +30,7 @@ def <<(key)
       self
     end
 
-  private
+    private
 
     # Define the equalizer methods based on #keys
     #
@@ -75,7 +73,8 @@ def define_hash_method
     #
     # @api private
     def define_inspect_method
-      name, keys = @name, @keys
+      name = @name
+      keys = @keys
       define_method(:inspect) do
         "#<#{name}#{keys.map { |key| " #{key}=#{send(key).inspect}" }.join}>"
       end
@@ -92,7 +91,6 @@ def include_comparison_methods
 
     # The comparison methods
     module Methods
-
       # Compare the object with other object for equality
       #
       # @example
@@ -120,9 +118,8 @@ def eql?(other)
       #
       # @api public
       def ==(other)
-        other.kind_of?(self.class) && cmp?(__method__, other)
+        other.is_a?(self.class) && cmp?(__method__, other)
       end
-
     end # module Methods
   end # class Equalizer
 end # module Virtus
diff --git a/lib/virtus/support/options.rb b/lib/virtus/support/options.rb
index 2a845abc..638d65b8 100644
--- a/lib/virtus/support/options.rb
+++ b/lib/virtus/support/options.rb
@@ -1,8 +1,6 @@
 module Virtus
-
   # A module that adds class and instance level options
   module Options
-
     # Returns default options hash for a given attribute class
     #
     # @example
@@ -51,7 +49,7 @@ def accept_options(*new_options)
       self
     end
 
-  protected
+    protected
 
     # Adds a reader/writer method for the give option name
     #
@@ -95,7 +93,7 @@ def add_accepted_options(new_options)
       self
     end
 
-  private
+    private
 
     # Adds descendant to descendants array and inherits default options
     #
@@ -108,6 +106,5 @@ def inherited(descendant)
       super
       descendant.add_accepted_options(accepted_options).set_options(options)
     end
-
   end # module Options
 end # module Virtus
diff --git a/lib/virtus/support/type_lookup.rb b/lib/virtus/support/type_lookup.rb
index a6ce2e39..b88f66a7 100644
--- a/lib/virtus/support/type_lookup.rb
+++ b/lib/virtus/support/type_lookup.rb
@@ -1,8 +1,6 @@
 module Virtus
-
   # A module that adds type lookup to a class
   module TypeLookup
-
     TYPE_FORMAT = /\A[A-Z]\w*\z/.freeze
 
     # Set cache ivar on the model
@@ -44,7 +42,7 @@ def primitive
       raise NotImplementedError, "#{self}.primitive must be implemented"
     end
 
-  private
+    private
 
     # @api private
     def determine_type_and_cache(class_or_name)
@@ -84,7 +82,7 @@ def determine_type_from_primitive(primitive)
       descendants.select(&:primitive).reverse_each do |descendant|
         descendant_primitive = descendant.primitive
         next unless primitive <= descendant_primitive
-        type = descendant if type.nil? or type.primitive > descendant_primitive
+        type = descendant if type.nil? || type.primitive > descendant_primitive
       end
       type
     end
@@ -100,10 +98,9 @@ def determine_type_from_primitive(primitive)
     #
     # @api private
     def determine_type_from_string(string)
-      if string =~ TYPE_FORMAT and const_defined?(string, *EXTRA_CONST_ARGS)
+      if string =~ TYPE_FORMAT && const_defined?(string, *EXTRA_CONST_ARGS)
         const_get(string, *EXTRA_CONST_ARGS)
       end
     end
-
   end # module TypeLookup
 end # module Virtus
diff --git a/lib/virtus/value_object.rb b/lib/virtus/value_object.rb
index 61c9b8fa..8419e414 100644
--- a/lib/virtus/value_object.rb
+++ b/lib/virtus/value_object.rb
@@ -1,5 +1,4 @@
 module Virtus
-
   # Include this Module for Value Object semantics
   #
   # The idea is that instances should be immutable and compared based on state
@@ -18,7 +17,6 @@ module Virtus
   #   hash = { location => :foo }
   #   hash[same_location]             #=> :foo
   module ValueObject
-
     # Callback to configure including Class as a Value Object
     #
     # Including Class will include Virtus and have additional
@@ -45,7 +43,6 @@ def self.included(base)
     private_class_method :included
 
     module InstanceMethods
-
       # ValueObjects are immutable and can't be cloned
       #
       # They always represent the same value
@@ -60,7 +57,7 @@ module InstanceMethods
       def clone
         self
       end
-      alias dup clone
+      alias_method :dup, :clone
 
       # Create a new ValueObject by combining the passed attribute hash with
       # the instances attributes.
@@ -77,7 +74,6 @@ def clone
       def with(attribute_updates)
         self.class.new(attribute_set.get(self).merge(attribute_updates))
       end
-
     end
 
     module AllowedWriterMethods
@@ -90,14 +86,13 @@ def allowed_writer_methods
         @allowed_writer_methods ||=
           begin
             allowed_writer_methods = super
-            allowed_writer_methods += attribute_set.map{|attr| "#{attr.name}="}
+            allowed_writer_methods += attribute_set.map { |attr| "#{attr.name}=" }
             allowed_writer_methods.to_set.freeze
           end
       end
     end
 
     module ClassMethods
-
       # Define an attribute on the receiver
       #
       # The Attribute will have private writer methods (eg., immutable instances)
@@ -142,9 +137,6 @@ def equalizer
             equalizer
           end
       end
-
     end # module ClassMethods
-
   end # module ValueObject
-
 end # module Virtus
diff --git a/spec/integration/attributes_attribute_spec.rb b/spec/integration/attributes_attribute_spec.rb
index 3c89e371..8c30fbff 100644
--- a/spec/integration/attributes_attribute_spec.rb
+++ b/spec/integration/attributes_attribute_spec.rb
@@ -1,27 +1,26 @@
 require 'spec_helper'
 
 describe "Adding attribute called 'attributes'" do
-
-  context "when mass assignment is disabled" do
+  context 'when mass assignment is disabled' do
     before do
       module Examples
         class User
-          include Virtus.model(mass_assignment: false)
+          include Virtus.model(:mass_assignment => false)
 
           attribute :attributes
         end
       end
     end
 
-    it "allows model to use `attributes` attribute" do
+    it 'allows model to use `attributes` attribute' do
       user = Examples::User.new
       expect(user.attributes).to eq(nil)
-      user.attributes = "attributes string"
-      expect(user.attributes).to eq("attributes string")
+      user.attributes = 'attributes string'
+      expect(user.attributes).to eq('attributes string')
     end
 
     it "doesn't accept `attributes` key in initializer" do
-      user = Examples::User.new(attributes: 'attributes string')
+      user = Examples::User.new(:attributes => 'attributes string')
       expect(user.attributes).to eq(nil)
     end
   end
diff --git a/spec/integration/building_module_spec.rb b/spec/integration/building_module_spec.rb
index ed492a21..1b86fa6e 100644
--- a/spec/integration/building_module_spec.rb
+++ b/spec/integration/building_module_spec.rb
@@ -3,25 +3,25 @@
 describe 'I can create a Virtus module' do
   before do
     module Examples
-      NoncoercingModule = Virtus.model { |config|
+      NoncoercingModule = Virtus.model do |config|
         config.coerce = false
-      }
+      end
 
-      CoercingModule = Virtus.model { |config|
+      CoercingModule = Virtus.model do |config|
         config.coerce = true
 
         config.coercer do |coercer|
           coercer.string.boolean_map = { 'yup' => true, 'nope' => false }
         end
-      }
+      end
 
-      StrictModule = Virtus.model { |config|
+      StrictModule = Virtus.model do |config|
         config.strict = true
-      }
+      end
 
-      BlankModule = Virtus.model { |config|
+      BlankModule = Virtus.model do |config|
         config.nullify_blank = true
-      }
+      end
 
       class NoncoercedUser
         include NoncoercingModule
diff --git a/spec/integration/collection_member_coercion_spec.rb b/spec/integration/collection_member_coercion_spec.rb
index f6ef068a..687805a5 100644
--- a/spec/integration/collection_member_coercion_spec.rb
+++ b/spec/integration/collection_member_coercion_spec.rb
@@ -31,18 +31,24 @@ class User
   it { is_expected.to respond_to(:addresses=) }
 
   let(:instance) do
-    described_class.new(:phone_numbers => phone_numbers_attributes,
-                        :addresses     => addresses_attributes)
+    described_class.new(
+      :phone_numbers => phone_numbers_attributes,
+      :addresses     => addresses_attributes
+    )
   end
 
-  let(:phone_numbers_attributes) { [
-    { :number => '212-555-1212' },
-    { :number => '919-444-3265' },
-  ] }
+  let(:phone_numbers_attributes) do
+    [
+      { :number => '212-555-1212' },
+      { :number => '919-444-3265' }
+    ]
+  end
 
-  let(:addresses_attributes) { [
-    { :address => '1234 Any St.', :locality => 'Anytown', :region => "DC", :postal_code => "21234" },
-  ] }
+  let(:addresses_attributes) do
+    [
+      { :address => '1234 Any St.', :locality => 'Anytown', :region => 'DC', :postal_code => '21234' }
+    ]
+  end
 
   describe '#phone_numbers' do
     describe 'first entry' do
@@ -80,17 +86,17 @@ class User
 
     describe '#locality' do
       subject { super().locality }
-      it { is_expected.to eql('Anytown')      }
+      it { is_expected.to eql('Anytown') }
     end
 
     describe '#region' do
       subject { super().region }
-      it { is_expected.to eql('DC')           }
+      it { is_expected.to eql('DC') }
     end
 
     describe '#postal_code' do
       subject { super().postal_code }
-      it { is_expected.to eql('21234')        }
+      it { is_expected.to eql('21234') }
     end
   end
 end
diff --git a/spec/integration/custom_attributes_spec.rb b/spec/integration/custom_attributes_spec.rb
index 3473d024..bd79060b 100644
--- a/spec/integration/custom_attributes_spec.rb
+++ b/spec/integration/custom_attributes_spec.rb
@@ -1,7 +1,6 @@
 require 'spec_helper'
 
 describe 'custom attributes' do
-
   before do
     module Examples
       class NoisyString < Virtus::Attribute
@@ -38,5 +37,4 @@ class User
     subject.scream = 'welcome'
     expect(subject.scream).to eq('WELCOME')
   end
-
 end
diff --git a/spec/integration/custom_collection_attributes_spec.rb b/spec/integration/custom_collection_attributes_spec.rb
index f267aa5d..bc62c47e 100644
--- a/spec/integration/custom_collection_attributes_spec.rb
+++ b/spec/integration/custom_collection_attributes_spec.rb
@@ -79,7 +79,7 @@ def books_should_be_an_empty_collection
   context 'with an enumerable' do
     require 'forwardable'
 
-    let(:book_collection_class) {
+    let(:book_collection_class) do
       Class.new do
         extend Forwardable
         include Enumerable
@@ -94,7 +94,7 @@ def self.[](*args)
           new(*args)
         end
       end
-    }
+    end
 
     it_behaves_like 'a collection'
   end
diff --git a/spec/integration/default_values_spec.rb b/spec/integration/default_values_spec.rb
index d9d9b1e8..ef1e299a 100644
--- a/spec/integration/default_values_spec.rb
+++ b/spec/integration/default_values_spec.rb
@@ -1,10 +1,8 @@
 require 'spec_helper'
 
-describe "default values" do
-
+describe 'default values' do
   before do
     module Examples
-
       class Reference
         include Virtus::ValueObject
 
@@ -15,7 +13,7 @@ class Page
         include Virtus
 
         attribute :title,        String
-        attribute :slug,         String,  :default => lambda { |post, attribute| post.title.downcase.gsub(' ', '-') }, :lazy => true
+        attribute :slug,         String,  :default => ->(post, _attribute) { post.title.downcase.tr(' ', '-') }, :lazy => true
         attribute :view_count,   Integer, :default => 0
         attribute :published,    Boolean, :default => false, :accessor => :private
         attribute :editor_title, String,  :default => :default_editor_title, :lazy => true
@@ -28,7 +26,6 @@ def default_editor_title
           published? ? title : "UNPUBLISHED: #{title}"
         end
       end
-
     end
   end
 
diff --git a/spec/integration/defining_attributes_spec.rb b/spec/integration/defining_attributes_spec.rb
index d0d711e5..75a8c88d 100644
--- a/spec/integration/defining_attributes_spec.rb
+++ b/spec/integration/defining_attributes_spec.rb
@@ -1,7 +1,6 @@
 require 'spec_helper'
 
-describe "virtus attribute definitions" do
-
+describe 'virtus attribute definitions' do
   before do
     module Examples
       class Person
@@ -14,7 +13,6 @@ class Person
       end
 
       class Manager < Person
-
       end
     end
   end
@@ -41,7 +39,7 @@ class Manager < Person
   end
 
   context 'with attributes' do
-    let(:attributes) { {:name => 'Jane', :age => 45, :doctor => true, :salary => 4500} }
+    let(:attributes) { { :name => 'Jane', :age => 45, :doctor => true, :salary => 4500 } }
 
     specify "#attributes returns the object's attributes as a hash" do
       expect(person.attributes).to eq(attributes)
diff --git a/spec/integration/embedded_value_spec.rb b/spec/integration/embedded_value_spec.rb
index f33b3477..7e65066f 100644
--- a/spec/integration/embedded_value_spec.rb
+++ b/spec/integration/embedded_value_spec.rb
@@ -26,17 +26,23 @@ class User
     end
   end
 
-  subject { Examples::User.new(:name => 'the guy',
-                               :address => address_attributes) }
+  subject do
+    Examples::User.new(:name    => 'the guy',
+                       :address => address_attributes)
+  end
   let(:address_attributes) do
-      { :street => 'Street 1/2', :zipcode => '12345', :city => { :name => 'NYC' } }
+    {
+      :street  => 'Street 1/2',
+      :zipcode => '12345',
+      :city    => { :name => 'NYC' }
+    }
   end
 
   specify '#attributes returns instances of the embedded values' do
-    expect(subject.attributes).to eq({
-      :name => 'the guy',
+    expect(subject.attributes).to eq(
+      :name    => 'the guy',
       :address => subject.address
-    })
+    )
   end
 
   specify 'allows you to pass a hash for the embedded value' do
@@ -46,5 +52,4 @@ class User
     expect(user.address.zipcode).to eq('12345')
     expect(user.address.city.name).to eq('NYC')
   end
-
 end
diff --git a/spec/integration/hash_attributes_coercion_spec.rb b/spec/integration/hash_attributes_coercion_spec.rb
index c225daa4..303f38a6 100644
--- a/spec/integration/hash_attributes_coercion_spec.rb
+++ b/spec/integration/hash_attributes_coercion_spec.rb
@@ -1,19 +1,24 @@
 require 'spec_helper'
 
-
 class Package
   include Virtus
 
   attribute :dimensions, Hash[Symbol => Float]
-  attribute :meta_info , Hash[String => String]
+  attribute :meta_info, Hash[String => String]
 end
 
-
 describe Package do
   let(:instance) do
     described_class.new(
-      :dimensions => { 'width' => "2.2", :height => 2, "length" => 4.5 },
-      :meta_info  => { 'from'  => :Me  , :to => 'You' }
+      :dimensions => {
+        'width'  => '2.2',
+        :height  => 2,
+        'length' => 4.5
+      },
+      :meta_info  => {
+        'from' => :Me,
+        :to    => 'You'
+      }
     )
   end
 
@@ -31,7 +36,7 @@ class Package
     it { is_expected.to have_key :length }
 
     it 'should be coerced to [Symbol => Float] format' do
-      expect(dimensions[:width]).to  be_eql(2.2)
+      expect(dimensions[:width]).to be_eql(2.2)
       expect(dimensions[:height]).to be_eql(2.0)
       expect(dimensions[:length]).to be_eql(4.5)
     end
diff --git a/spec/integration/inheritance_spec.rb b/spec/integration/inheritance_spec.rb
index 068466af..547118d4 100644
--- a/spec/integration/inheritance_spec.rb
+++ b/spec/integration/inheritance_spec.rb
@@ -9,7 +9,7 @@ class Base
 
       class First < Base
         attribute :id, Fixnum
-        attribute :name, String, default: ->(first, _) { "Named: #{first.id}" }
+        attribute :name, String, :default => ->(first, _) { "Named: #{first.id}" }
         attribute :description, String
       end
 
diff --git a/spec/integration/injectible_coercers_spec.rb b/spec/integration/injectible_coercers_spec.rb
index bf891733..2101f112 100644
--- a/spec/integration/injectible_coercers_spec.rb
+++ b/spec/integration/injectible_coercers_spec.rb
@@ -7,7 +7,7 @@ class EmailAddress
         include Virtus.value_object
 
         values do
-          attribute :address, String, :coercer => lambda { |add| add.downcase }
+          attribute :address, String, :coercer => ->(add) { add.downcase }
         end
 
         def self.coerce(input)
@@ -23,7 +23,7 @@ class User
         include Virtus.model
 
         attribute :email, EmailAddress,
-          :coercer => lambda { |input| Examples::EmailAddress.coerce(input) }
+                  :coercer => ->(input) { Examples::EmailAddress.coerce(input) }
       end
     end
   end
@@ -44,5 +44,4 @@ class User
     user = Examples::User.new :email => 'John.Doe@Example.Com'
     expect(user.email).to eq(doe)
   end
-
 end
diff --git a/spec/integration/mass_assignment_with_accessors_spec.rb b/spec/integration/mass_assignment_with_accessors_spec.rb
index 72e1124e..63b006e6 100644
--- a/spec/integration/mass_assignment_with_accessors_spec.rb
+++ b/spec/integration/mass_assignment_with_accessors_spec.rb
@@ -1,7 +1,6 @@
 require 'spec_helper'
 
-describe "mass assignment with accessors" do
-
+describe 'mass assignment with accessors' do
   before do
     module Examples
       class Product
@@ -16,7 +15,7 @@ def categories=(categories)
           self.subcategory = categories.last
         end
 
-      private
+        private
 
         def _id=(value)
           self.id = value
@@ -25,7 +24,7 @@ def _id=(value)
     end
   end
 
-  subject { Examples::Product.new(:categories => ['Office', 'Printers'], :_id => 100) }
+  subject { Examples::Product.new(:categories => %w(Office Printers), :_id => 100) }
 
   specify 'works uppon instantiation' do
     expect(subject.category).to eq('Office')
@@ -33,7 +32,7 @@ def _id=(value)
   end
 
   specify 'can be set with #attributes=' do
-    subject.attributes = {:categories => ['Home', 'Furniture']}
+    subject.attributes = { :categories => %w(Home Furniture) }
     expect(subject.category).to eq('Home')
     expect(subject.subcategory).to eq('Furniture')
   end
diff --git a/spec/integration/overriding_virtus_spec.rb b/spec/integration/overriding_virtus_spec.rb
index d02b8f3d..84c0dbb6 100644
--- a/spec/integration/overriding_virtus_spec.rb
+++ b/spec/integration/overriding_virtus_spec.rb
@@ -1,7 +1,6 @@
 require 'spec_helper'
 
 describe 'overriding virtus behavior' do
-
   before do
     module Examples
       class Article
@@ -14,7 +13,7 @@ def title
         end
 
         def title=(name)
-          super unless self.title == "can't be changed"
+          super unless title == "can't be changed"
         end
       end
     end
diff --git a/spec/integration/struct_as_embedded_value_spec.rb b/spec/integration/struct_as_embedded_value_spec.rb
index f83465a5..384793c4 100644
--- a/spec/integration/struct_as_embedded_value_spec.rb
+++ b/spec/integration/struct_as_embedded_value_spec.rb
@@ -15,7 +15,7 @@ class Rectangle
   end
 
   subject do
-    Examples::Rectangle.new(:top_left => [ 3, 5 ], :bottom_right => [ 8, 7 ])
+    Examples::Rectangle.new(:top_left => [3, 5], :bottom_right => [8, 7])
   end
 
   specify 'initialize a struct object with correct attributes' do
diff --git a/spec/integration/using_modules_spec.rb b/spec/integration/using_modules_spec.rb
index 0abb59f3..ea0bf772 100644
--- a/spec/integration/using_modules_spec.rb
+++ b/spec/integration/using_modules_spec.rb
@@ -17,7 +17,7 @@ module Name
       module Age
         include Common
 
-        attribute :age,  Integer
+        attribute :age, Integer
       end
 
       class User
diff --git a/spec/integration/value_object_with_custom_constructor_spec.rb b/spec/integration/value_object_with_custom_constructor_spec.rb
index 0be0a883..910efcfd 100644
--- a/spec/integration/value_object_with_custom_constructor_spec.rb
+++ b/spec/integration/value_object_with_custom_constructor_spec.rb
@@ -1,6 +1,6 @@
 require 'spec_helper'
 
-describe "Defining a ValueObject with a custom constructor" do
+describe 'Defining a ValueObject with a custom constructor' do
   before do
     module Examples
       class Point
@@ -10,7 +10,7 @@ class Point
         attribute :y, Integer
 
         def initialize(attributes)
-          if attributes.kind_of?(Array)
+          if attributes.is_a?(Array)
             self.x = attributes.first
             self.y = attributes.last
           else
@@ -29,10 +29,10 @@ class Rectangle
   end
 
   subject do
-    Examples::Rectangle.new(:top_left => [ 3, 4 ], :bottom_right => [ 5, 8 ])
+    Examples::Rectangle.new(:top_left => [3, 4], :bottom_right => [5, 8])
   end
 
-  specify "initialize a value object attribute with correct attributes" do
+  specify 'initialize a value object attribute with correct attributes' do
     expect(subject.top_left.x).to be(3)
     expect(subject.top_left.y).to be(4)
 
diff --git a/spec/integration/virtus/value_object_spec.rb b/spec/integration/virtus/value_object_spec.rb
index 100de421..7669ba3c 100644
--- a/spec/integration/virtus/value_object_spec.rb
+++ b/spec/integration/virtus/value_object_spec.rb
@@ -26,7 +26,7 @@ def self.name
 
   describe 'initialization' do
     it 'sets the attribute values provided to Class.new' do
-      expect(class_under_test.new(:latitude => 10000.001).latitude).to eq(10000.001)
+      expect(class_under_test.new(:latitude => 10_000.001).latitude).to eq(10_000.001)
       expect(subject.latitude).to eql(attribute_values[:latitude])
     end
   end
@@ -39,7 +39,7 @@ def self.name
 
     it 'writer methods are set to private' do
       private_methods = class_under_test.private_instance_methods
-      private_methods.map! { |m| m.to_s }
+      private_methods.map!(&:to_s)
       expect(private_methods).to include('latitude=', 'longitude=', 'attributes=')
     end
 
diff --git a/spec/shared/constants_helpers.rb b/spec/shared/constants_helpers.rb
index 0e30ade1..17cebad1 100644
--- a/spec/shared/constants_helpers.rb
+++ b/spec/shared/constants_helpers.rb
@@ -1,5 +1,4 @@
 module ConstantsHelpers
-
   extend self
 
   # helper to remove constants after test-runs.
diff --git a/spec/shared/freeze_method_behavior.rb b/spec/shared/freeze_method_behavior.rb
index 6b50f745..c475dabf 100644
--- a/spec/shared/freeze_method_behavior.rb
+++ b/spec/shared/freeze_method_behavior.rb
@@ -25,7 +25,7 @@
 
   it 'prevents future modifications' do
     subject
-    expectation = raise_error(expected_exception_class,expected_exception_message)
+    expectation = raise_error(expected_exception_class, expected_exception_message)
     expect { object.instance_variable_set(:@foo, :bar) }.to(expectation)
   end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 7bd9c881..9c0ca846 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,5 +1,5 @@
-if RUBY_ENGINE == "rbx"
-  require "codeclimate-test-reporter"
+if RUBY_ENGINE == 'rbx'
+  require 'codeclimate-test-reporter'
   CodeClimate::TestReporter.start
 end
 
@@ -22,7 +22,7 @@ def self.warn(*)
 RSpec.configure do |config|
   # Remove anonymous- and example- Attribute classes from Attribute descendants
   config.after :all do
-    stack = [ Virtus::Attribute ]
+    stack = [Virtus::Attribute]
     while klass = stack.pop
       klass.descendants.delete_if do |descendant|
         descendant.name.nil? || descendant.name.empty? || descendant.name.start_with?('Examples::')
diff --git a/spec/unit/virtus/attribute/coerce_spec.rb b/spec/unit/virtus/attribute/coerce_spec.rb
index a9d11906..0afe6444 100644
--- a/spec/unit/virtus/attribute/coerce_spec.rb
+++ b/spec/unit/virtus/attribute/coerce_spec.rb
@@ -5,10 +5,10 @@
 
   fake(:coercer) { Virtus::Attribute::Coercer }
 
-  let(:object)   {
+  let(:object)   do
     described_class.build(String,
-      :coercer => coercer, :strict => strict, :required => required, :nullify_blank => nullify_blank)
-  }
+                          :coercer => coercer, :strict => strict, :required => required, :nullify_blank => nullify_blank)
+  end
 
   let(:required) { true }
   let(:nullify_blank) { false }
diff --git a/spec/unit/virtus/attribute/collection/class_methods/build_spec.rb b/spec/unit/virtus/attribute/collection/class_methods/build_spec.rb
index 417ad64b..245d41db 100644
--- a/spec/unit/virtus/attribute/collection/class_methods/build_spec.rb
+++ b/spec/unit/virtus/attribute/collection/class_methods/build_spec.rb
@@ -96,7 +96,7 @@
 
   context 'when strict mode is used' do
     let(:type) { Array[String] }
-    let(:options) { { strict: true } }
+    let(:options) { { :strict => true } }
 
     it 'sets strict mode for member type' do
       expect(subject.member_type).to be_strict
diff --git a/spec/unit/virtus/attribute/collection/coerce_spec.rb b/spec/unit/virtus/attribute/collection/coerce_spec.rb
index e4ad256a..d9f0e756 100644
--- a/spec/unit/virtus/attribute/collection/coerce_spec.rb
+++ b/spec/unit/virtus/attribute/collection/coerce_spec.rb
@@ -9,11 +9,11 @@
       fake(:member_type) { Virtus::Attribute }
 
       let(:member_primitive) { Integer }
-      let(:input)            { ['1', '2'] }
+      let(:input)            { %w(1 2) }
 
-      let(:object) {
+      let(:object) do
         described_class.build(Array[member_primitive], :coercer => coercer, :member_type => member_type)
-      }
+      end
 
       it 'uses coercer to coerce members' do
         mock(coercer).call(input) { input }
@@ -41,7 +41,7 @@
     context 'when member type is a hash with key/value coercion' do
       let(:member_primitive) { Hash[String => Integer] }
       let(:member_attribute) { Virtus::Attribute.build(member_primitive) }
-      let(:input)            { [{:one => '1'}, {:two => '2'}] }
+      let(:input)            { [{ :one => '1' }, { :two => '2' }] }
       let(:output)           { [member_attribute.coerce(input.first), member_attribute.coerce(input.last)] }
       let(:object)           { described_class.build(Array[member_primitive]) }
 
@@ -59,11 +59,11 @@
 
     let(:member_primitive) { Integer }
 
-    let(:object) {
+    let(:object) do
       described_class.build(
-        Array[member_primitive], coercer: coercer, member_type: member_type
+        Array[member_primitive], :coercer => coercer, :member_type => member_type
       )
-    }
+    end
 
     it 'returns nil' do
       mock(coercer).call(input) { input }
diff --git a/spec/unit/virtus/attribute/custom_collection_spec.rb b/spec/unit/virtus/attribute/custom_collection_spec.rb
index 423d2b50..2d616307 100644
--- a/spec/unit/virtus/attribute/custom_collection_spec.rb
+++ b/spec/unit/virtus/attribute/custom_collection_spec.rb
@@ -3,7 +3,7 @@
 describe Virtus::Attribute::Collection, 'custom subclass' do
   subject { attribute_class.build(primitive) }
 
-  let(:primitive) { Class.new  { include Enumerable } }
+  let(:primitive) { Class.new { include Enumerable } }
 
   after do
     described_class.descendants.delete(attribute_class)
diff --git a/spec/unit/virtus/attribute/embedded_value/coerce_spec.rb b/spec/unit/virtus/attribute/embedded_value/coerce_spec.rb
index 34670690..fd343a4a 100644
--- a/spec/unit/virtus/attribute/embedded_value/coerce_spec.rb
+++ b/spec/unit/virtus/attribute/embedded_value/coerce_spec.rb
@@ -7,10 +7,10 @@
   let(:options) { {} }
 
   context 'when primitive is OpenStruct' do
-    let(:model)  { OpenStruct }
+    let(:model) { OpenStruct }
 
     context 'when input is an attribute hash' do
-      let(:input) { Hash[name: 'Piotr', age: 30] }
+      let(:input) { Hash[:name => 'Piotr', :age => 30] }
 
       it { is_expected.to be_instance_of(model) }
 
@@ -39,7 +39,7 @@
   end
 
   context 'when primitive is Struct' do
-    let(:model)  { Struct.new(:name, :age) }
+    let(:model) { Struct.new(:name, :age) }
 
     context 'when input is an attribute hash' do
       let(:input) { ['Piotr', 30] }
diff --git a/spec/unit/virtus/attribute/hash/coerce_spec.rb b/spec/unit/virtus/attribute/hash/coerce_spec.rb
index 502cea4f..5cbbc5ca 100644
--- a/spec/unit/virtus/attribute/hash/coerce_spec.rb
+++ b/spec/unit/virtus/attribute/hash/coerce_spec.rb
@@ -7,14 +7,20 @@
   fake(:key_type)   { Virtus::Attribute }
   fake(:value_type) { Virtus::Attribute }
 
-  let(:object) {
+  let(:object) do
     described_class.build(Hash[key_primitive => value_primitive], options)
-  }
+  end
 
   let(:options) { {} }
 
   context 'when input is coercible to hash' do
-    let(:input)  { Class.new { def to_hash; { :hello => 'World' }; end }.new }
+    let(:input) do
+      Class.new do
+        def to_hash
+          { :hello => 'World' }
+        end
+      end.new
+    end
     let(:object) { described_class.build(Hash) }
 
     it { is_expected.to eq(:hello => 'World') }
@@ -29,9 +35,9 @@
 
   context 'when input is a hash' do
     context 'when key/value types are primitives' do
-      let(:options) {
+      let(:options) do
         { :coercer => coercer, :key_type => key_type, :value_type => value_type }
-      }
+      end
 
       let(:key_primitive)   { String }
       let(:value_primitive) { Integer }
@@ -63,7 +69,7 @@
       let(:key_primitive)   { OpenStruct }
       let(:value_primitive) { Struct.new(:id) }
 
-      let(:input)  { Hash[{:name => 'Test'} => [1]] }
+      let(:input)  { Hash[{ :name => 'Test' } => [1]] }
       let(:output) { Hash[key_primitive.new(:name => 'Test') => value_primitive.new(1)] }
 
       it 'coerces keys and values' do
@@ -81,7 +87,7 @@
       let(:key_attribute)   { Virtus::Attribute.build(key_primitive) }
       let(:value_attribute) { Virtus::Attribute.build(value_primitive) }
 
-      let(:input)  { Hash[[1, 2], {:one => '1', :two => '2'}] }
+      let(:input)  { Hash[[1, 2], { :one => '1', :two => '2' }] }
       let(:output) { Hash[key_attribute.coerce(input.keys.first) => value_attribute.coerce(input.values.first)] }
 
       it 'coerces keys and values' do
diff --git a/spec/unit/virtus/attribute/set_default_value_spec.rb b/spec/unit/virtus/attribute/set_default_value_spec.rb
index 9151b846..c6419c2c 100644
--- a/spec/unit/virtus/attribute/set_default_value_spec.rb
+++ b/spec/unit/virtus/attribute/set_default_value_spec.rb
@@ -3,7 +3,16 @@
 describe Virtus::Attribute, '#set_default_value' do
   let(:object) { described_class.build(String, options.merge(:name => name, :default => default)) }
 
-  let(:model)    { Class.new { def name; 'model'; end; attr_reader :test } }
+  let(:model) do
+    Class.new do
+      def name
+        'model'
+      end
+
+      attr_reader :test
+    end
+  end
+
   let(:name)     { :test }
   let(:instance) { model.new }
   let(:options)  { {} }
@@ -62,7 +71,7 @@
   context 'with a callable' do
     subject { instance }
 
-    let(:default) { lambda { |model, attribute| "#{model.name}-#{attribute.name}" } }
+    let(:default) { ->(model, attribute) { "#{model.name}-#{attribute.name}" } }
 
     describe '#test' do
       subject { super().test }
@@ -77,7 +86,15 @@
       let(:default) { :set_test }
 
       context 'when method is public' do
-        let(:model) { Class.new { attr_reader :test; def set_test; @test = 'hello world'; end } }
+        let(:model) do
+          Class.new do
+            attr_reader :test
+
+            def set_test
+              @test = 'hello world'
+            end
+          end
+        end
 
         describe '#test' do
           subject { super().test }
@@ -86,7 +103,17 @@
       end
 
       context 'when method is private' do
-        let(:model) { Class.new { attr_reader :test; private; def set_test; @test = 'hello world'; end } }
+        let(:model) do
+          Class.new do
+            attr_reader :test
+
+            private
+
+            def set_test
+              @test = 'hello world'
+            end
+          end
+        end
 
         describe '#test' do
           subject { super().test }
diff --git a/spec/unit/virtus/attribute/value_coerced_predicate_spec.rb b/spec/unit/virtus/attribute/value_coerced_predicate_spec.rb
index 3cd8c649..2b173e2c 100644
--- a/spec/unit/virtus/attribute/value_coerced_predicate_spec.rb
+++ b/spec/unit/virtus/attribute/value_coerced_predicate_spec.rb
@@ -6,13 +6,13 @@
   let(:object) { described_class.build(String) }
 
   context 'when input is coerced' do
-    let(:input)  { '1' }
+    let(:input) { '1' }
 
     it { is_expected.to be(true) }
   end
 
   context 'when input is not coerced' do
-    let(:input)  { 1 }
+    let(:input) { 1 }
 
     it { is_expected.to be(false) }
   end
diff --git a/spec/unit/virtus/attribute_set/append_spec.rb b/spec/unit/virtus/attribute_set/append_spec.rb
index 577b07ed..68b34207 100644
--- a/spec/unit/virtus/attribute_set/append_spec.rb
+++ b/spec/unit/virtus/attribute_set/append_spec.rb
@@ -14,21 +14,21 @@
     it { is_expected.to equal(object) }
 
     it 'adds an attribute' do
-      expect { subject }.to change { object.to_a }.
-        from(attributes).
-        to([ attribute ])
+      expect { subject }.to change { object.to_a }
+        .from(attributes)
+        .to([attribute])
     end
 
     it 'indexes the new attribute under its #name property' do
-      expect { subject }.to change { object[name] }.
-        from(nil).
-        to(attribute)
+      expect { subject }.to change { object[name] }
+        .from(nil)
+        .to(attribute)
     end
 
     it 'indexes the new attribute under the string version of its #name property' do
-      expect { subject }.to change { object[name.to_s] }.
-        from(nil).
-        to(attribute)
+      expect { subject }.to change { object[name.to_s] }
+        .from(nil)
+        .to(attribute)
     end
   end
 
@@ -38,10 +38,10 @@
 
     it { is_expected.to equal(object) }
 
-    it "replaces the original attribute object" do
-      expect { subject }.to change { object.to_a.map(&:__id__) }.
-      from(attributes.map(&:__id__)).
-      to([attribute.__id__])
+    it 'replaces the original attribute object' do
+      expect { subject }.to change { object.to_a.map(&:__id__) }
+        .from(attributes.map(&:__id__))
+        .to([attribute.__id__])
     end
   end
 end
diff --git a/spec/unit/virtus/attribute_set/define_reader_method_spec.rb b/spec/unit/virtus/attribute_set/define_reader_method_spec.rb
index 4fd58acc..812d6cec 100644
--- a/spec/unit/virtus/attribute_set/define_reader_method_spec.rb
+++ b/spec/unit/virtus/attribute_set/define_reader_method_spec.rb
@@ -10,26 +10,26 @@
     attribute_set.define_reader_method(attribute, method_name, visibility)
   end
 
-  context "with public visibility" do
+  context 'with public visibility' do
     let(:visibility) { :public }
 
-    it "defines public writer" do
+    it 'defines public writer' do
       expect(attribute_set.public_instance_methods).to include(method_name)
     end
   end
 
-  context "with private visibility" do
+  context 'with private visibility' do
     let(:visibility) { :private }
 
-    it "defines public writer" do
+    it 'defines public writer' do
       expect(attribute_set.private_instance_methods).to include(method_name)
     end
   end
 
-  context "with protected visibility" do
+  context 'with protected visibility' do
     let(:visibility) { :protected }
 
-    it "defines protected writer" do
+    it 'defines protected writer' do
       expect(attribute_set.protected_instance_methods).to include(method_name)
     end
   end
diff --git a/spec/unit/virtus/attribute_set/define_writer_method_spec.rb b/spec/unit/virtus/attribute_set/define_writer_method_spec.rb
index 4814a03e..31530305 100644
--- a/spec/unit/virtus/attribute_set/define_writer_method_spec.rb
+++ b/spec/unit/virtus/attribute_set/define_writer_method_spec.rb
@@ -10,26 +10,26 @@
     attribute_set.define_writer_method(attribute, method_name, visibility)
   end
 
-  context "with public visibility" do
+  context 'with public visibility' do
     let(:visibility) { :public }
 
-    it "defines public writer" do
+    it 'defines public writer' do
       expect(attribute_set.public_instance_methods).to include(method_name)
     end
   end
 
-  context "with private visibility" do
+  context 'with private visibility' do
     let(:visibility) { :private }
 
-    it "defines private writer" do
+    it 'defines private writer' do
       expect(attribute_set.private_instance_methods).to include(method_name)
     end
   end
 
-  context "with protected visibility" do
+  context 'with protected visibility' do
     let(:visibility) { :protected }
 
-    it "defines protected writer" do
+    it 'defines protected writer' do
       expect(attribute_set.protected_instance_methods).to include(method_name)
     end
   end
diff --git a/spec/unit/virtus/attribute_set/each_spec.rb b/spec/unit/virtus/attribute_set/each_spec.rb
index 86c9fd6b..7ffebc0a 100644
--- a/spec/unit/virtus/attribute_set/each_spec.rb
+++ b/spec/unit/virtus/attribute_set/each_spec.rb
@@ -5,7 +5,7 @@
 
   let(:name)       { :name }
   let(:attribute)  { Virtus::Attribute.build(String, :name => :name) }
-  let(:attributes) { [ attribute ] }
+  let(:attributes) { [attribute] }
   let(:parent)     { described_class.new }
   let(:yields)     { Set[] }
 
@@ -28,15 +28,15 @@
       it { is_expected.to equal(attribute_set) }
 
       it 'yields the expected attributes' do
-        expect { subject }.to change { yields.dup }.
-          from(Set[]).
-          to(attributes.to_set)
+        expect { subject }.to change { yields.dup }
+          .from(Set[])
+          .to(attributes.to_set)
       end
     end
 
     context 'when the parent has attributes that are not duplicates' do
       let(:parent_attribute) { Virtus::Attribute.build(String, :name => :parent_name) }
-      let(:parent)           { described_class.new([ parent_attribute ])       }
+      let(:parent)           { described_class.new([parent_attribute]) }
 
       it { is_expected.to equal(attribute_set) }
 
@@ -51,14 +51,14 @@
 
     context 'when the parent has attributes that are duplicates' do
       let(:parent_attribute) { Virtus::Attribute.build(String, :name => name) }
-      let(:parent)           { described_class.new([ parent_attribute ]) }
+      let(:parent)           { described_class.new([parent_attribute]) }
 
       it { is_expected.to equal(attribute_set) }
 
       it 'yields the expected attributes' do
-        expect { subject }.to change { yields.dup }.
-          from(Set[]).
-          to(Set[ attribute ])
+        expect { subject }.to change { yields.dup }
+          .from(Set[])
+          .to(Set[attribute])
       end
     end
   end
diff --git a/spec/unit/virtus/attribute_set/element_reference_spec.rb b/spec/unit/virtus/attribute_set/element_reference_spec.rb
index 73fc3e24..6c852446 100644
--- a/spec/unit/virtus/attribute_set/element_reference_spec.rb
+++ b/spec/unit/virtus/attribute_set/element_reference_spec.rb
@@ -3,9 +3,9 @@
 describe Virtus::AttributeSet, '#[]' do
   subject { object[name] }
 
-  let(:name)       { :name                                   }
+  let(:name)       { :name }
   let(:attribute)  { Virtus::Attribute.build(String, :name => :name) }
-  let(:attributes) { [ attribute ]                           }
+  let(:attributes) { [attribute]                           }
   let(:parent)     { described_class.new                     }
   let(:object)     { described_class.new(parent, attributes) }
 
diff --git a/spec/unit/virtus/attribute_set/element_set_spec.rb b/spec/unit/virtus/attribute_set/element_set_spec.rb
index 8d9c6385..e7d6b2da 100644
--- a/spec/unit/virtus/attribute_set/element_set_spec.rb
+++ b/spec/unit/virtus/attribute_set/element_set_spec.rb
@@ -14,7 +14,7 @@
     it { is_expected.to equal(attribute) }
 
     it 'adds an attribute' do
-      expect { subject }.to change { object.to_a }.from(attributes).to([ attribute ])
+      expect { subject }.to change { object.to_a }.from(attributes).to([attribute])
     end
 
     it 'allows #[] to access the attribute with a symbol' do
@@ -26,39 +26,39 @@
     end
 
     it 'allows #reset to track overridden attributes' do
-      expect { subject }.to change { object.reset.to_a }.from(attributes).to([ attribute ])
+      expect { subject }.to change { object.reset.to_a }.from(attributes).to([attribute])
     end
   end
 
   context 'with a duplicate attribute' do
     let(:original)   { Virtus::Attribute.build(String, :name => name) }
-    let(:attributes) { [ original ] }
+    let(:attributes) { [original] }
     let(:attribute)  { Virtus::Attribute.build(String, :name => name) }
 
     it { is_expected.to equal(attribute) }
 
-    it "replaces the original attribute object" do
-      expect { subject }.to change { object.to_a.map(&:__id__) }.
-      from(attributes.map(&:__id__)).
-      to([attribute.__id__])
+    it 'replaces the original attribute object' do
+      expect { subject }.to change { object.to_a.map(&:__id__) }
+        .from(attributes.map(&:__id__))
+        .to([attribute.__id__])
     end
 
     it 'allows #[] to access the attribute with a string' do
-      expect { subject }.to change { object['name'].__id__ }.
-      from(original.__id__).
-      to(attribute.__id__)
+      expect { subject }.to change { object['name'].__id__ }
+        .from(original.__id__)
+        .to(attribute.__id__)
     end
 
     it 'allows #[] to access the attribute with a symbol' do
-      expect { subject }.to change { object[:name].__id__ }.
-      from(original.__id__).
-      to(attribute.__id__)
+      expect { subject }.to change { object[:name].__id__ }
+        .from(original.__id__)
+        .to(attribute.__id__)
     end
 
     it 'allows #reset to track overridden attributes' do
-      expect { subject }.to change { object.reset.to_a.map(&:__id__) }.
-      from(attributes.map(&:__id__)).
-      to([attribute.__id__])
+      expect { subject }.to change { object.reset.to_a.map(&:__id__) }
+        .from(attributes.map(&:__id__))
+        .to([attribute.__id__])
     end
   end
 end
diff --git a/spec/unit/virtus/attribute_set/merge_spec.rb b/spec/unit/virtus/attribute_set/merge_spec.rb
index 9981ece8..3ef8880a 100644
--- a/spec/unit/virtus/attribute_set/merge_spec.rb
+++ b/spec/unit/virtus/attribute_set/merge_spec.rb
@@ -25,10 +25,10 @@
 
     it { is_expected.to equal(object) }
 
-    it "replaces the original attribute object" do
-      expect { subject }.to change { object.to_a.map(&:__id__) }.
-      from(attributes.map(&:__id__)).
-      to([attribute.__id__])
+    it 'replaces the original attribute object' do
+      expect { subject }.to change { object.to_a.map(&:__id__) }
+        .from(attributes.map(&:__id__))
+        .to([attribute.__id__])
     end
   end
 end
diff --git a/spec/unit/virtus/attribute_set/reset_spec.rb b/spec/unit/virtus/attribute_set/reset_spec.rb
index b0d6698f..d5ce7f6e 100644
--- a/spec/unit/virtus/attribute_set/reset_spec.rb
+++ b/spec/unit/virtus/attribute_set/reset_spec.rb
@@ -5,7 +5,7 @@
 
   let(:name)       { :name }
   let(:attribute)  { Virtus::Attribute.build(String, :name => :name) }
-  let(:attributes) { [ attribute ]                           }
+  let(:attributes) { [attribute]                           }
   let(:object)     { described_class.new(parent, attributes) }
 
   context 'when the parent has no attributes' do
@@ -15,37 +15,37 @@
 
     describe '#to_set' do
       subject { super().to_set }
-      it { is_expected.to eq(Set[ attribute ]) }
+      it { is_expected.to eq(Set[attribute]) }
     end
   end
 
   context 'when the parent has attributes that are not duplicates' do
     let(:parent_attribute) { Virtus::Attribute.build(String, :name => :parent_name) }
-    let(:parent)           { described_class.new([ parent_attribute ])       }
+    let(:parent)           { described_class.new([parent_attribute]) }
 
     it { is_expected.to equal(object) }
 
     describe '#to_set' do
       subject { super().to_set }
-      it { is_expected.to eq(Set[ attribute, parent_attribute ]) }
+      it { is_expected.to eq(Set[attribute, parent_attribute]) }
     end
   end
 
   context 'when the parent has attributes that are duplicates' do
     let(:parent_attribute) { Virtus::Attribute.build(String, :name => name) }
-    let(:parent)           { described_class.new([ parent_attribute ]) }
+    let(:parent)           { described_class.new([parent_attribute]) }
 
     it { is_expected.to equal(object) }
 
     describe '#to_set' do
       subject { super().to_set }
-      it { is_expected.to eq(Set[ attribute ]) }
+      it { is_expected.to eq(Set[attribute]) }
     end
   end
 
   context 'when the parent has changed' do
     let(:parent_attribute) { Virtus::Attribute.build(String, :name => :parent_name) }
-    let(:parent)           { described_class.new([ parent_attribute ])       }
+    let(:parent)           { described_class.new([parent_attribute]) }
     let(:new_attribute)    { Virtus::Attribute.build(String, :name => :parent_name) }
 
     it { is_expected.to equal(object) }
diff --git a/spec/unit/virtus/attribute_spec.rb b/spec/unit/virtus/attribute_spec.rb
index f280e9c8..2b369b72 100644
--- a/spec/unit/virtus/attribute_spec.rb
+++ b/spec/unit/virtus/attribute_spec.rb
@@ -163,13 +163,13 @@ class Test
   end
 
   context 'with a module' do
-    let(:mod) {
-      Module.new {
+    let(:mod) do
+      Module.new do
         include Virtus
 
         attribute :test, String
-      }
-    }
+      end
+    end
 
     let(:model) { Class.new }
 
@@ -210,13 +210,13 @@ class Test
   context 'using custom module' do
     subject { model.new }
 
-    let(:model) {
-      Class.new {
+    let(:model) do
+      Class.new do
         include Virtus.model { |config| config.coerce = false }
 
         attribute :test, String
-      }
-    }
+      end
+    end
 
     it { is_expected.to respond_to(:test) }
     it { is_expected.to respond_to(:test=) }
diff --git a/spec/unit/virtus/attributes_reader_spec.rb b/spec/unit/virtus/attributes_reader_spec.rb
index 82774c37..953205d1 100644
--- a/spec/unit/virtus/attributes_reader_spec.rb
+++ b/spec/unit/virtus/attributes_reader_spec.rb
@@ -1,7 +1,6 @@
 require 'spec_helper'
 
 describe Virtus, '#attributes' do
-
   shared_examples_for 'attribute hash' do
     it 'includes all attributes' do
       subject.attributes = { :test => 'Hello World', :test_priv => 'Yo' }
@@ -11,14 +10,14 @@
   end
 
   context 'with a class' do
-    let(:model) {
-      Class.new {
+    let(:model) do
+      Class.new do
         include Virtus
 
         attribute :test,      String
         attribute :test_priv, String, :reader => :private
-      }
-    }
+      end
+    end
 
     it_behaves_like 'attribute hash' do
       subject { model.new }
diff --git a/spec/unit/virtus/attributes_writer_spec.rb b/spec/unit/virtus/attributes_writer_spec.rb
index e52ec1ac..5cc6857b 100644
--- a/spec/unit/virtus/attributes_writer_spec.rb
+++ b/spec/unit/virtus/attributes_writer_spec.rb
@@ -1,7 +1,6 @@
 require 'spec_helper'
 
 describe Virtus, '#attributes=' do
-
   shared_examples_for 'mass-assignment' do
     it 'allows writing known attributes' do
       subject.attributes = { :test => 'Hello World' }
@@ -17,13 +16,13 @@
   end
 
   context 'with a class' do
-    let(:model) {
-      Class.new {
+    let(:model) do
+      Class.new do
         include Virtus
 
         attribute :test, String
-      }
-    }
+      end
+    end
 
     it_behaves_like 'mass-assignment' do
       subject { model.new }
diff --git a/spec/unit/virtus/class_methods/new_spec.rb b/spec/unit/virtus/class_methods/new_spec.rb
index 63ca576b..bda5865c 100644
--- a/spec/unit/virtus/class_methods/new_spec.rb
+++ b/spec/unit/virtus/class_methods/new_spec.rb
@@ -1,15 +1,15 @@
 require 'spec_helper'
 
 describe Virtus, '.new' do
-  let(:model) {
-    Class.new {
+  let(:model) do
+    Class.new do
       include Virtus
 
       attribute :id,    Integer
       attribute :name,  String, :default => 'John Doe'
       attribute :email, String, :default => 'john@doe.com', :lazy => true, :writer => :private
-    }
-  }
+    end
+  end
 
   context 'without attribute hash' do
     subject { model.new }
@@ -35,5 +35,4 @@
       expect(subject.instance_variable_get('@email')).to be(nil)
     end
   end
-
 end
diff --git a/spec/unit/virtus/element_reader_spec.rb b/spec/unit/virtus/element_reader_spec.rb
index 7353c00a..129671e0 100644
--- a/spec/unit/virtus/element_reader_spec.rb
+++ b/spec/unit/virtus/element_reader_spec.rb
@@ -3,13 +3,13 @@
 describe Virtus, '#[]' do
   subject { object[:test] }
 
-  let(:model) {
-    Class.new {
+  let(:model) do
+    Class.new do
       include Virtus
 
       attribute :test, String
-    }
-  }
+    end
+  end
 
   let(:object) { model.new }
 
diff --git a/spec/unit/virtus/element_writer_spec.rb b/spec/unit/virtus/element_writer_spec.rb
index 44af0299..76e309af 100644
--- a/spec/unit/virtus/element_writer_spec.rb
+++ b/spec/unit/virtus/element_writer_spec.rb
@@ -3,13 +3,13 @@
 describe Virtus, '#[]=' do
   subject { object[:test] = 'foo' }
 
-  let(:model) {
-    Class.new {
+  let(:model) do
+    Class.new do
       include Virtus
 
       attribute :test, String
-    }
-  }
+    end
+  end
 
   let(:object) { model.new }
 
diff --git a/spec/unit/virtus/freeze_spec.rb b/spec/unit/virtus/freeze_spec.rb
index aa018f99..6d50c642 100644
--- a/spec/unit/virtus/freeze_spec.rb
+++ b/spec/unit/virtus/freeze_spec.rb
@@ -3,15 +3,15 @@
 describe Virtus, '#freeze' do
   subject { object.freeze }
 
-  let(:model) {
-    Class.new {
+  let(:model) do
+    Class.new do
       include Virtus
 
       attribute :name, String,  :default => 'foo', :lazy => true
       attribute :age,  Integer, :default => 30
-      attribute :rand, Float,   :default => Proc.new { rand }
-    }
-  }
+      attribute :rand, Float,   :default => proc { rand }
+    end
+  end
 
   let(:object) { model.new }
 
@@ -27,13 +27,13 @@
     it { is_expected.to be(30) }
   end
 
-  it "does not change dynamic default values" do
+  it 'does not change dynamic default values' do
     original_value = object.rand
     object.freeze
     expect(object.rand).to eq original_value
   end
 
-  it "does not change default attributes that have been explicitly set" do
+  it 'does not change default attributes that have been explicitly set' do
     object.rand = 3.14
     object.freeze
     expect(object.rand).to eq 3.14
diff --git a/spec/unit/virtus/model_spec.rb b/spec/unit/virtus/model_spec.rb
index 0bfcc1e5..09ce80ca 100644
--- a/spec/unit/virtus/model_spec.rb
+++ b/spec/unit/virtus/model_spec.rb
@@ -68,9 +68,9 @@
         it_behaves_like 'a model with mass-assignment' do
           let(:instance) { subject.new }
 
-          let(:attributes) {
+          let(:attributes) do
             { :name => 'Jane', :something => nil, :age => 23 }
-          }
+          end
         end
 
         it 'has its own attributes' do
diff --git a/spec/unit/virtus/module_spec.rb b/spec/unit/virtus/module_spec.rb
index 74bf59ea..4cb167fd 100644
--- a/spec/unit/virtus/module_spec.rb
+++ b/spec/unit/virtus/module_spec.rb
@@ -116,7 +116,7 @@
 
   context 'as a peer to another module within a class' do
     subject { Virtus.module }
-    let(:other)  { Module.new }
+    let(:other) { Module.new }
 
     before do
       other.send(:include, Virtus.module)
@@ -142,8 +142,8 @@
 
   context 'with multiple other modules mixed into it' do
     subject { Virtus.module }
-    let(:other)  { Module.new }
-    let(:yet_another)  { Module.new }
+    let(:other) { Module.new }
+    let(:yet_another) { Module.new }
 
     before do
       other.send(:include, Virtus.module)
@@ -170,5 +170,4 @@
       )
     end
   end
-
 end
diff --git a/spec/unit/virtus/set_default_attributes_spec.rb b/spec/unit/virtus/set_default_attributes_spec.rb
index ee059012..26a31475 100644
--- a/spec/unit/virtus/set_default_attributes_spec.rb
+++ b/spec/unit/virtus/set_default_attributes_spec.rb
@@ -3,14 +3,14 @@
 describe Virtus, '#set_default_attributes!' do
   subject { object.set_default_attributes! }
 
-  let(:model) {
-    Class.new {
+  let(:model) do
+    Class.new do
       include Virtus
 
       attribute :name, String,  :default => 'foo', :lazy => true
       attribute :age,  Integer, :default => 30
-    }
-  }
+    end
+  end
 
   let(:object) { model.new }
 
diff --git a/spec/unit/virtus/value_object_spec.rb b/spec/unit/virtus/value_object_spec.rb
index e536a676..1d04f4c5 100644
--- a/spec/unit/virtus/value_object_spec.rb
+++ b/spec/unit/virtus/value_object_spec.rb
@@ -44,9 +44,9 @@
     end
 
     it 'allows to construct new values using #with' do
-      new_instance = subject.with(:name => "John Doe")
+      new_instance = subject.with(:name => 'John Doe')
       expect(new_instance.id).to eql(subject.id)
-      expect(new_instance.name).to eql("John Doe")
+      expect(new_instance.name).to eql('John Doe')
     end
   end
 
@@ -59,10 +59,10 @@
   end
 
   context 'using new values {} block' do
-    let(:model) {
+    let(:model) do
       model = Virtus.value_object(:coerce => false, :mass_assignment => mass_assignment)
 
-      Class.new {
+      Class.new do
         include model
 
         def self.name
@@ -73,8 +73,8 @@ def self.name
           attribute :id,   Integer
           attribute :name, String
         end
-      }
-    }
+      end
+    end
 
     context 'without mass-assignment' do
       let(:mass_assignment) { false }
@@ -89,13 +89,13 @@ def self.name
       it_behaves_like 'a valid value object with mass-assignment turned on'
 
       context 'with a model subclass' do
-        let(:subclass) {
-          Class.new(model) {
+        let(:subclass) do
+          Class.new(model) do
             values do
               attribute :email, String
             end
-          }
-        }
+          end
+        end
 
         it_behaves_like 'a valid value object' do
           subject { subclass.new(attributes) }
@@ -120,8 +120,8 @@ def self.name
   end
 
   context 'using deprecated inclusion' do
-    let(:model) {
-      Class.new {
+    let(:model) do
+      Class.new do
         include Virtus::ValueObject
 
         def self.name
@@ -130,8 +130,8 @@ def self.name
 
         attribute :id,   Integer
         attribute :name, String
-      }
-    }
+      end
+    end
 
     it_behaves_like 'a valid value object'
   end
diff --git a/virtus.gemspec b/virtus.gemspec
index d73ba617..9eb566e4 100644
--- a/virtus.gemspec
+++ b/virtus.gemspec
@@ -3,19 +3,19 @@
 require File.expand_path('../lib/virtus/version', __FILE__)
 
 Gem::Specification.new do |gem|
-  gem.name        = "virtus"
+  gem.name        = 'virtus'
   gem.version     = Virtus::VERSION.dup
-  gem.authors     = [ "Piotr Solnica" ]
-  gem.email       = [ "piotr.solnica@gmail.com" ]
-  gem.description = "Attributes on Steroids for Plain Old Ruby Objects"
+  gem.authors     = ['Piotr Solnica']
+  gem.email       = ['piotr.solnica@gmail.com']
+  gem.description = 'Attributes on Steroids for Plain Old Ruby Objects'
   gem.summary     = gem.description
-  gem.homepage    = "https://github.com/solnic/virtus"
+  gem.homepage    = 'https://github.com/solnic/virtus'
   gem.license     = 'MIT'
 
-  gem.require_paths    = [ "lib" ]
+  gem.require_paths    = ['lib']
   gem.files            = `git ls-files`.split("\n")
   gem.test_files       = `git ls-files -- {spec}/*`.split("\n")
-  gem.extra_rdoc_files = %w[LICENSE README.md TODO.md]
+  gem.extra_rdoc_files = %w(LICENSE README.md TODO.md)
 
   gem.add_dependency('descendants_tracker', '~> 0.0', '>= 0.0.3')
   gem.add_dependency('equalizer', '~> 0.0', '>= 0.0.9')