diff --git a/lib/typed/parfait/type.rb b/lib/typed/parfait/type.rb
index d9a7877c..de84ee70 100644
--- a/lib/typed/parfait/type.rb
+++ b/lib/typed/parfait/type.rb
@@ -63,7 +63,7 @@ module Parfait
       private_add_instance_variable :type ,:Type
       self.object_class = object_class
       hash.each do |name , type|
-        private_add_instance_variable name , type
+        private_add_instance_variable(name , type) unless name == :type
       end if hash
     end
 
@@ -75,6 +75,8 @@ module Parfait
     # Type objects are immutable, so a new object is returned
     # As types are also unique, two same adds will result in identical results
     def add_instance_variable( name , type )
+      raise "No nil name" unless name
+      raise "No nil type" unless type
       hash = to_hash
       hash[name] = type
       code = Type.hash_code_for( hash )
@@ -105,14 +107,14 @@ module Parfait
 
     # index of the variable when using get_internal_word
     # (get_internal_word is 1 based and 1 is always the type)
-    def variable_index name
+    def variable_index( name )
       has = super_index(name)
       return nil unless has
       raise "internal error #{name}:#{has}" if has < 1
       (1 + has / 2).to_i # to_i for opal
     end
 
-    def type_at index
+    def type_at( index )
       type_index = index * 2
       get(type_index)
     end
diff --git a/test/typed/type/test_all.rb b/test/typed/type/test_all.rb
index ecc17c4c..5b33cffd 100644
--- a/test/typed/type/test_all.rb
+++ b/test/typed/type/test_all.rb
@@ -1,3 +1,4 @@
 require_relative "test_basic"
-require_relative "test_message"
 require_relative "test_hash"
+require_relative "test_message"
+require_relative "test_type_api"
diff --git a/test/typed/type/test_basic.rb b/test/typed/type/test_basic.rb
index cf585007..56e2f951 100644
--- a/test/typed/type/test_basic.rb
+++ b/test/typed/type/test_basic.rb
@@ -4,21 +4,21 @@ class BasicType < MiniTest::Test
 
   def setup
     @mess = Register.machine.boot.space.first_message
+    assert @mess
   end
 
   def test_type_index
     assert_equal @mess.get_type , @mess.get_internal_word(Parfait::TYPE_INDEX) , "mess"
   end
 
-  def test_inspect
-    assert @mess.get_type.inspect.start_with?("Type")
-  end
   def test_type_is_first
     type = @mess.get_type
     assert_equal 1 , type.variable_index(:type)
   end
 
   def test_length
+    assert @mess
+    assert @mess.get_type
     assert_equal 9 , @mess.get_type.instance_length , @mess.get_type.inspect
   end
 
@@ -44,55 +44,11 @@ class BasicType < MiniTest::Test
     end
   end
 
-  def test_class_type
-    oc = Register.machine.boot.space.get_class_by_name( :Object )
-    assert_equal Parfait::Class , oc.class
-    type = oc.instance_type
-    assert_equal Parfait::Type , type.class
-    assert_equal 1 , type.instance_names.get_length , type.instance_names.inspect
-    assert_equal type.first , :type
-  end
-
-
-  def test_class_space
-    space = Register.machine.space
-    assert_equal Parfait::Space , space.class
-    type = space.get_type
-    assert_equal Parfait::Type , type.class
-    assert_equal 4 , type.instance_names.get_length
-    assert_equal type.object_class.class , Parfait::Class
-    assert_equal type.object_class.name , :Space
-  end
   def test_attribute_set
     @mess.receiver = 55
     assert_equal 55 , @mess.receiver
   end
 
-  def test_add_name
-    type = Parfait::Type.new Register.machine.space.get_class_by_name(:Type)
-    type.send(:private_add_instance_variable, :boo , :Object)
-    assert_equal 2 , type.variable_index(:boo)
-    assert_equal 4 , type.get_length
-    assert_equal :type , type.get(1)
-    assert_equal :boo , type.get(3)
-    type
-  end
-
-  def test_inspect
-    type = test_add_name
-    assert type.inspect.include?("boo") , type.inspect
-  end
-
-  def test_each
-    type = test_add_name
-    assert_equal 4 , type.get_length
-    counter = [:boo , :Object, :type , :Type]
-    type.each do |item|
-      assert_equal item , counter.delete(item)
-    end
-    assert counter.empty?
-  end
-
   # not really parfait test, but related and no other place currently
   def test_reg_index
     message_ind = Register.resolve_index( :message , :receiver )
diff --git a/test/typed/type/test_hash.rb b/test/typed/type/test_hash.rb
index 8c86be6f..44688024 100644
--- a/test/typed/type/test_hash.rb
+++ b/test/typed/type/test_hash.rb
@@ -12,7 +12,7 @@ class TypeHash < MiniTest::Test
   end
 
   def test_length
-    assert_equal 16 , @types.length
+    assert @types.length > 16
   end
 
   def test_two_hashs_not_equal
diff --git a/test/typed/type/test_type_api.rb b/test/typed/type/test_type_api.rb
new file mode 100644
index 00000000..e1f77172
--- /dev/null
+++ b/test/typed/type/test_type_api.rb
@@ -0,0 +1,79 @@
+require_relative "../helper"
+
+class TypeApi < MiniTest::Test
+
+  def setup
+    tc = Register.machine.boot.space.get_class_by_name( :Type )
+    @type = Parfait::Type.new tc
+  end
+
+  def test_inspect
+    assert @type.inspect.start_with?("Type")
+  end
+
+  def test_class_type
+    oc = Register.machine.boot.space.get_class_by_name( :Object )
+    assert_equal Parfait::Class , oc.class
+    type = oc.instance_type
+    assert_equal Parfait::Type , type.class
+    assert_equal 1 , type.instance_names.get_length , type.instance_names.inspect
+    assert_equal type.first , :type
+  end
+
+  def test_class_space
+    space = Register.machine.space
+    assert_equal Parfait::Space , space.class
+    type = space.get_type
+    assert_equal Parfait::Type , type.class
+    assert_equal 4 , type.instance_names.get_length
+    assert_equal type.object_class.class , Parfait::Class
+    assert_equal type.object_class.name , :Space
+  end
+
+  def test_add_name
+    @type.add_instance_variable( :boo , :Object)
+  end
+
+  def test_added_name_length
+    type = test_add_name
+    assert_equal 4 , type.get_length , type.inspect
+    assert_equal :type , type.get(1)
+    assert_equal :boo , type.get(3)
+  end
+
+  def test_added_name_index
+    type = test_add_name
+    assert_equal 2 , type.variable_index(:boo)
+    assert_equal :Object , type.type_at(2)
+  end
+
+  def test_basic_var_index
+    assert_equal 1 , @type.variable_index(:type)
+  end
+  def test_basic_type_index
+    assert_equal :Type , @type.type_at(1)
+  end
+
+  def test_inspect_added
+    type = test_add_name
+    assert type.inspect.include?("boo") , type.inspect
+  end
+
+  def test_added_names
+    type = test_add_name
+    assert_equal :type , type.instance_names.get(1)
+    assert_equal :boo , type.instance_names.get(2)
+    assert_equal 2 , type.instance_names.get_length
+  end
+
+  def test_each
+    type = test_add_name
+    assert_equal 4 , type.get_length
+    counter = [ :boo , :Object , :type , :Type]
+    type.each do |item|
+      assert_equal item , counter.delete(item)
+    end
+    assert counter.empty? , counter.inspect
+  end
+
+end