diff --git a/Gemfile b/Gemfile
index 7007c896..7ac769fd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,6 +3,7 @@ source 'https://rubygems.org'
 gemspec
 
 gem 'immutable', :git => 'https://github.com/mbj/immutable'
+gem 'abstract',  :git => 'https://github.com/mbj/abstract'
 
 # Until there is a release with explicit sends to self fix
 gem 'to_source', :git => 'https://github.com/mbj/to_source'
diff --git a/lib/mutant.rb b/lib/mutant.rb
index 12df9a4b..1d791320 100644
--- a/lib/mutant.rb
+++ b/lib/mutant.rb
@@ -1,4 +1,5 @@
 require 'immutable'
+require 'abstract'
 require 'securerandom'
 require 'to_source'
 require 'ice_nine'
@@ -33,7 +34,6 @@ module Mutant
   end
 end
 
-require 'mutant/support/abstract'
 require 'mutant/random'
 require 'mutant/runner'
 #require 'mutant/runner/rspec'
diff --git a/lib/mutant/context.rb b/lib/mutant/context.rb
index 40717ade..365d1dfd 100644
--- a/lib/mutant/context.rb
+++ b/lib/mutant/context.rb
@@ -1,8 +1,7 @@
 module Mutant
   # An abstract context where mutations can be appied to.
   class Context
-    include Immutable
-    extend Abstract
+    include Immutable, Abstract
 
     # Return root ast for mutated node
     #
@@ -12,6 +11,6 @@ module Mutant
     #
     # @api private
     #
-    abstract :root
+    abstract_method :root
   end
 end
diff --git a/lib/mutant/matcher.rb b/lib/mutant/matcher.rb
index fadf5c26..88ba7383 100644
--- a/lib/mutant/matcher.rb
+++ b/lib/mutant/matcher.rb
@@ -1,8 +1,7 @@
 module Mutant
   # Abstract matcher to find ASTs to mutate
   class Matcher
-    include Enumerable
-    extend Abstract
+    include Enumerable, Abstract
 
     # Enumerate subjects
     #
@@ -10,7 +9,7 @@ module Mutant
     #
     # @return [undefined]
     #
-    abstract :each
+    abstract_method :each
 
   private
 
diff --git a/lib/mutant/matcher/method.rb b/lib/mutant/matcher/method.rb
index 0c6c1b00..569bd8a5 100644
--- a/lib/mutant/matcher/method.rb
+++ b/lib/mutant/matcher/method.rb
@@ -86,7 +86,7 @@ module Mutant
       #
       # @api private
       #
-      abstract :method
+      abstract_method :method
 
       # Return node classes this matcher matches
       #
@@ -94,7 +94,7 @@ module Mutant
       #
       # @api private
       #
-      abstract :node_class
+      abstract_method :node_class
 
       # Check if node is matched
       #
@@ -160,7 +160,7 @@ module Mutant
       #
       # @api private
       #
-      abstract :matched_node
+      abstract_method :matched_node
 
       # Return subject
       #
diff --git a/lib/mutant/mutator.rb b/lib/mutant/mutator.rb
index 526e8a01..8a176d92 100644
--- a/lib/mutant/mutator.rb
+++ b/lib/mutant/mutator.rb
@@ -1,8 +1,7 @@
 module Mutant
   # Generator for mutations
   class Mutator
-    include Immutable
-    extend Abstract
+    include Immutable, Abstract
 
     # Enumerate mutations on node
     #
@@ -65,7 +64,7 @@ module Mutant
     #
     # @api private
     #
-    abstract :dispatch
+    abstract_method :dispatch
 
     # Append node to generated mutations if node does not equal orignal node
     #
diff --git a/lib/mutant/mutator/literal/boolean.rb b/lib/mutant/mutator/literal/boolean.rb
index 04f75076..2b2bdf06 100644
--- a/lib/mutant/mutator/literal/boolean.rb
+++ b/lib/mutant/mutator/literal/boolean.rb
@@ -23,7 +23,7 @@ module Mutant
         #
         # @api private
         #
-        abstract :inverse
+        abstract_method :inverse
 
         # Represent mutations of true literal
         class TrueLiteral < Boolean
diff --git a/lib/mutant/mutator/literal/range.rb b/lib/mutant/mutator/literal/range.rb
index a0e69ffc..6e8b554e 100644
--- a/lib/mutant/mutator/literal/range.rb
+++ b/lib/mutant/mutator/literal/range.rb
@@ -48,7 +48,7 @@ module Mutant
         #
         # @api private
         #
-        abstract :inverse_class
+        abstract_method :inverse_class
 
         # Mutator for range exclude literals
         class Exclude < Range
diff --git a/lib/mutant/runner.rb b/lib/mutant/runner.rb
index da767943..45d33fa7 100644
--- a/lib/mutant/runner.rb
+++ b/lib/mutant/runner.rb
@@ -1,8 +1,7 @@
 module Mutant
   # Abstract runner for tests
   class Runner
-    include Immutable
-    extend Abstract
+    include Immutable, Abstract
 
     # Run runner
     #
@@ -75,6 +74,6 @@ module Mutant
     #
     # @api private
     #
-    abstract :run
+    abstract_method :run
   end
 end
diff --git a/lib/mutant/support/abstract.rb b/lib/mutant/support/abstract.rb
deleted file mode 100644
index 5497a99b..00000000
--- a/lib/mutant/support/abstract.rb
+++ /dev/null
@@ -1,67 +0,0 @@
-module Mutant
-  # Module to declare abstract methods
-  module Abstract
-
-    # Declare abstract instance method
-    #
-    # @return [self]
-    #
-    # @api private
-    #
-    def abstract(*names)
-      names.each do |name|
-        define_instance_method(name)
-      end
-
-      self
-    end
-
-    # Declare abstract singleton method
-    #
-    # @return [self]
-    #
-    # @api private
-    #
-    def abstract_singleton(*names)
-      names.each do |name|
-        define_singleton_method(name)
-      end
-
-      self
-    end
-
-  private
-
-    # Define abstract method stub on singleton
-    #
-    # @param [String] name
-    #
-    # @return [undefined]
-    #
-    # @api private
-    #
-    def define_singleton_method(name)
-      class_eval(<<-RUBY, __FILE__, __LINE__+1)
-        def #{name}(*)
-          raise NotImplementedError, "\#{self.name}.\#{__method__} is not implemented"
-        end
-      RUBY
-    end
-
-    # Define abstract method stub on instances
-    #
-    # @param [String] name
-    #
-    # @return [undefined]
-    #
-    # @api private
-    #
-    def define_instance_method(name)
-      class_eval(<<-RUBY, __FILE__, __LINE__+1)
-        def #{name}(*)
-          raise NotImplementedError, "\#{self.class.name}#\#{__method__} is not implemented"
-        end
-      RUBY
-    end
-  end
-end
diff --git a/mutant.gemspec b/mutant.gemspec
index 32d7ac06..4513d2b7 100644
--- a/mutant.gemspec
+++ b/mutant.gemspec
@@ -16,7 +16,9 @@ Gem::Specification.new do |gem|
   gem.test_files       = `git ls-files -- spec`.split("\n")
   gem.extra_rdoc_files = %w[TODO]
 
-  gem.add_dependency('to_source', '~> 0.1.3')
-  gem.add_dependency('ice_nine', '~> 0.4.0')
+  gem.add_runtime_dependency('to_source', '~> 0.1.3')
+  gem.add_runtime_dependency('ice_nine',  '~> 0.4.0')
   gem.add_runtime_dependency('backports', '~> 2.6')
+  gem.add_runtime_dependency('immutable', '~> 0.0.1')
+  gem.add_runtime_dependency('abstract',  '~> 0.0.1')
 end