diff --git a/lib/mutant/context/constant.rb b/lib/mutant/context/constant.rb
index 43da5b24..cd5019ba 100644
--- a/lib/mutant/context/constant.rb
+++ b/lib/mutant/context/constant.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Context
     # Constant context for mutation (Class or Module)
-    class Constant < Context
+    class Constant < self
       include Immutable
 
       private_class_method :new
diff --git a/lib/mutant/matcher/method.rb b/lib/mutant/matcher/method.rb
index 569bd8a5..4699e842 100644
--- a/lib/mutant/matcher/method.rb
+++ b/lib/mutant/matcher/method.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Matcher
     # Matcher to find AST for method
-    class Method < Matcher
+    class Method < self
       include Immutable
 
       # Parse a method string into filter
diff --git a/lib/mutant/matcher/method/classifier.rb b/lib/mutant/matcher/method/classifier.rb
index 57d8af36..9e0e27ac 100644
--- a/lib/mutant/matcher/method/classifier.rb
+++ b/lib/mutant/matcher/method/classifier.rb
@@ -1,6 +1,6 @@
 module Mutant
   class Matcher
-    class Method < Matcher
+    class Method < self
       # A classifier for input strings
       class Classifier
         extend Immutable
diff --git a/lib/mutant/matcher/method/instance.rb b/lib/mutant/matcher/method/instance.rb
index 5d92209f..260f1399 100644
--- a/lib/mutant/matcher/method/instance.rb
+++ b/lib/mutant/matcher/method/instance.rb
@@ -1,8 +1,8 @@
 module Mutant
   class Matcher
-    class Method < Matcher
+    class Method < self
       # Matcher for instance methods
-      class Instance < Method
+      class Instance < self
 
       private
 
diff --git a/lib/mutant/matcher/method/singleton.rb b/lib/mutant/matcher/method/singleton.rb
index 2378316f..d6ea2049 100644
--- a/lib/mutant/matcher/method/singleton.rb
+++ b/lib/mutant/matcher/method/singleton.rb
@@ -2,7 +2,7 @@ module Mutant
   class Matcher
     class Method
       # Matcher for singleton methods
-      class Singleton < Method
+      class Singleton < self
 
       private
 
diff --git a/lib/mutant/mutator/block.rb b/lib/mutant/mutator/block.rb
index 9cc84474..7153af1a 100644
--- a/lib/mutant/mutator/block.rb
+++ b/lib/mutant/mutator/block.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Mutator
     # Mutator on AST blocks
-    class Block < Mutator
+    class Block < self
 
       handle Rubinius::AST::Block
 
diff --git a/lib/mutant/mutator/call.rb b/lib/mutant/mutator/call.rb
index bb74883b..6999f6ae 100644
--- a/lib/mutant/mutator/call.rb
+++ b/lib/mutant/mutator/call.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Mutator
     # Abstract class for mutatiosn where messages are send
-    class Call < Mutator
+    class Call < self
 
       handle(Rubinius::AST::Send)
 
diff --git a/lib/mutant/mutator/if_statement.rb b/lib/mutant/mutator/if_statement.rb
index 867ea6f7..33cead53 100644
--- a/lib/mutant/mutator/if_statement.rb
+++ b/lib/mutant/mutator/if_statement.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Mutator
     # Mutator for Rubinius::AST::If nodes
-    class IfStatement < Mutator
+    class IfStatement < self
 
       handle(Rubinius::AST::If)
 
diff --git a/lib/mutant/mutator/literal.rb b/lib/mutant/mutator/literal.rb
index cb303d10..7ec5429f 100644
--- a/lib/mutant/mutator/literal.rb
+++ b/lib/mutant/mutator/literal.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Mutator
     # Abstract mutator for literal AST nodes
-    class Literal < Mutator
+    class Literal < self
 
     private
 
diff --git a/lib/mutant/mutator/literal/array.rb b/lib/mutant/mutator/literal/array.rb
index bbbe2846..1787eaee 100644
--- a/lib/mutant/mutator/literal/array.rb
+++ b/lib/mutant/mutator/literal/array.rb
@@ -1,8 +1,8 @@
 module Mutant
   class Mutator
-    class Literal < Mutator
+    class Literal < self
       # Mutator for array literals
-      class Array < Literal
+      class Array < self
 
         handle(Rubinius::AST::ArrayLiteral)
 
diff --git a/lib/mutant/mutator/literal/boolean.rb b/lib/mutant/mutator/literal/boolean.rb
index a2d640f5..0a67d66a 100644
--- a/lib/mutant/mutator/literal/boolean.rb
+++ b/lib/mutant/mutator/literal/boolean.rb
@@ -1,8 +1,8 @@
 module Mutant
   class Mutator
-    class Literal < Mutator
+    class Literal < self
       # Abstract mutator for boolean literals
-      class Boolean < Literal
+      class Boolean < self
 
       private
 
@@ -28,7 +28,7 @@ module Mutant
         end
 
         # Represent mutations of true literal
-        class TrueLiteral < Boolean
+        class TrueLiteral < self
           INVERSE_CLASS = Rubinius::AST::FalseLiteral
 
           handle(Rubinius::AST::TrueLiteral)
@@ -36,7 +36,7 @@ module Mutant
 
 
         # Represent mutations of false literal
-        class FalseLiteral < Boolean
+        class FalseLiteral < self
           INVERSE_CLASS = Rubinius::AST::TrueLiteral
 
           handle(Rubinius::AST::FalseLiteral)
diff --git a/lib/mutant/mutator/literal/dynamic.rb b/lib/mutant/mutator/literal/dynamic.rb
index 2da8af5f..f99c5807 100644
--- a/lib/mutant/mutator/literal/dynamic.rb
+++ b/lib/mutant/mutator/literal/dynamic.rb
@@ -2,7 +2,7 @@ module Mutant
   class Mutator
     class Literal
       # Abstract mutations on dynamic literals
-      class Dynamic < Literal
+      class Dynamic < self
 
       private
 
diff --git a/lib/mutant/mutator/literal/empty_array.rb b/lib/mutant/mutator/literal/empty_array.rb
index b90bd296..8ab4ce7f 100644
--- a/lib/mutant/mutator/literal/empty_array.rb
+++ b/lib/mutant/mutator/literal/empty_array.rb
@@ -1,8 +1,8 @@
 module Mutant
   class Mutator
-    class Literal < Mutator
+    class Literal < self
       # Mutator for empty array literals
-      class EmptyArray < Literal
+      class EmptyArray < self
 
         handle(Rubinius::AST::EmptyArray)
 
diff --git a/lib/mutant/mutator/literal/fixnum.rb b/lib/mutant/mutator/literal/fixnum.rb
index fb42dcaa..5f2cf044 100644
--- a/lib/mutant/mutator/literal/fixnum.rb
+++ b/lib/mutant/mutator/literal/fixnum.rb
@@ -1,8 +1,8 @@
 module Mutant
   class Mutator
-    class Literal < Mutator
+    class Literal < self
       # Represent mutations on fixnum literal
-      class Fixnum < Literal
+      class Fixnum < self
 
         handle(Rubinius::AST::FixnumLiteral)
 
diff --git a/lib/mutant/mutator/literal/float.rb b/lib/mutant/mutator/literal/float.rb
index 26fa1810..4d18db3e 100644
--- a/lib/mutant/mutator/literal/float.rb
+++ b/lib/mutant/mutator/literal/float.rb
@@ -1,8 +1,8 @@
 module Mutant
   class Mutator
-    class Literal < Mutator
+    class Literal < self
       # Represent mutations on fixnum literal
-      class Float < Literal
+      class Float < self
 
         handle(Rubinius::AST::FloatLiteral)
 
diff --git a/lib/mutant/mutator/literal/hash.rb b/lib/mutant/mutator/literal/hash.rb
index 5693629d..6795ce9f 100644
--- a/lib/mutant/mutator/literal/hash.rb
+++ b/lib/mutant/mutator/literal/hash.rb
@@ -2,7 +2,7 @@ module Mutant
   class Mutator
       class Literal
       # Mutator for hash literal AST nodes
-      class Hash < Mutator
+      class Hash < self
 
         handle(Rubinius::AST::HashLiteral)
 
diff --git a/lib/mutant/mutator/literal/range.rb b/lib/mutant/mutator/literal/range.rb
index 6e8b554e..3e8a4954 100644
--- a/lib/mutant/mutator/literal/range.rb
+++ b/lib/mutant/mutator/literal/range.rb
@@ -2,7 +2,7 @@ module Mutant
   class Mutator
     class Literal
       # Abstract literal range mutator
-      class Range < Literal
+      class Range < self
 
       private
 
@@ -51,7 +51,7 @@ module Mutant
         abstract_method :inverse_class
 
         # Mutator for range exclude literals
-        class Exclude < Range
+        class Exclude < self
 
           handle(Rubinius::AST::RangeExclude)
 
@@ -69,7 +69,7 @@ module Mutant
         end
 
         # Mutator for range literals
-        class Include < Range
+        class Include < self
 
           handle(Rubinius::AST::Range)
 
diff --git a/lib/mutant/mutator/literal/regex.rb b/lib/mutant/mutator/literal/regex.rb
index 14fd666a..a60922c6 100644
--- a/lib/mutant/mutator/literal/regex.rb
+++ b/lib/mutant/mutator/literal/regex.rb
@@ -1,8 +1,8 @@
 module Mutant
   class Mutator
-    class Literal < Mutator
+    class Literal < self
       # Mutator for regexp literal AST nodes
-      class Regex < Literal
+      class Regex < self
 
         handle(Rubinius::AST::RegexLiteral)
 
diff --git a/lib/mutant/mutator/literal/string.rb b/lib/mutant/mutator/literal/string.rb
index 1511107c..f88b0b4b 100644
--- a/lib/mutant/mutator/literal/string.rb
+++ b/lib/mutant/mutator/literal/string.rb
@@ -2,7 +2,7 @@ module Mutant
   class Mutator
     class Literal
       # Represent mutations on string literal
-      class String < Literal
+      class String < self
 
         handle(Rubinius::AST::StringLiteral)
 
diff --git a/lib/mutant/mutator/literal/symbol.rb b/lib/mutant/mutator/literal/symbol.rb
index 06415f4a..e67e39ea 100644
--- a/lib/mutant/mutator/literal/symbol.rb
+++ b/lib/mutant/mutator/literal/symbol.rb
@@ -1,8 +1,8 @@
 module Mutant
   class Mutator
-    class Literal < Mutator
+    class Literal < self
       # Represent mutations on symbol literal
-      class Symbol < Literal
+      class Symbol < self
 
         handle(Rubinius::AST::SymbolLiteral)
 
diff --git a/lib/mutant/mutator/noop.rb b/lib/mutant/mutator/noop.rb
index 0738e718..e944dd91 100644
--- a/lib/mutant/mutator/noop.rb
+++ b/lib/mutant/mutator/noop.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Mutator
     # Mutator that does do not mutations on ast
-    class Noop < Mutator
+    class Noop < self
 
       # Literal references to self do not need to be mutated. 
       handle(Rubinius::AST::Self)
diff --git a/lib/mutant/mutator/receiver_case.rb b/lib/mutant/mutator/receiver_case.rb
index 5daaa3b3..b9e3dda2 100644
--- a/lib/mutant/mutator/receiver_case.rb
+++ b/lib/mutant/mutator/receiver_case.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Mutator
     # Mutator for Rubinius::AST::When nodes
-    class When < Mutator
+    class When < self
 
       handle(Rubinius::AST::When)
 
@@ -33,7 +33,7 @@ module Mutant
     end
 
     # Mutator for Rubinius::AST::ReceiverCase nodes
-    class ReceiverCase < Mutator
+    class ReceiverCase < self
 
       handle(Rubinius::AST::ReceiverCase)
 
diff --git a/lib/mutant/runner/rspec.rb b/lib/mutant/runner/rspec.rb
index 171a5d48..4b375001 100644
--- a/lib/mutant/runner/rspec.rb
+++ b/lib/mutant/runner/rspec.rb
@@ -1,7 +1,7 @@
 module Mutant
   class Runner
     # Simple runner for rspec tests
-    class Rspec < Runner
+    class Rspec < self
 
       # Return error stream
       #