diff --git a/lib/parfait/typed_method.rb b/lib/parfait/typed_method.rb
index 370ce96c..4dcae2f8 100644
--- a/lib/parfait/typed_method.rb
+++ b/lib/parfait/typed_method.rb
@@ -62,28 +62,6 @@ module Parfait
       @cpu_instructions
     end
 
-    # determine whether this method has an argument by the name
-    def has_argument( name )
-      raise "has_argument #{name}.#{name.class}" unless name.is_a? Symbol
-      index = arguments_type.variable_index( name )
-      index ? (index - 1) : index
-    end
-
-    def add_argument(name , type)
-      @arguments_type = @arguments_type.add_instance_variable(name,type)
-    end
-
-    def arguments_length
-      arguments_type.instance_length - 1
-    end
-
-    def argument_name( index )
-      arguments_type.names.get(index + 1)
-    end
-    def argument_type( index )
-      arguments_type.types.get(index + 1)
-    end
-
     # determine if method has a local variable or tmp (anonymous local) by given name
     def has_local( name )
       raise "has_local #{name}.#{name.class}" unless name.is_a? Symbol
diff --git a/test/parfait/test_typed_method.rb b/test/parfait/test_typed_method.rb
index 06542ccd..47060a71 100644
--- a/test/parfait/test_typed_method.rb
+++ b/test/parfait/test_typed_method.rb
@@ -20,40 +20,40 @@ module Parfait
     end
 
     def test_arg1
-      assert_equal 2 , @method.arguments_length , @method.arguments_type.inspect
+      assert_equal 3 , @method.arguments_type.get_length , @method.arguments_type.inspect
       assert_equal Symbol , @method.arguments_type.names.first.class
-      assert_equal :bar , @method.argument_name(0)
+      assert_equal :bar , @method.arguments_type.name_at(1)
     end
 
     def test_has_argument
-      assert_equal 0 , @method.has_argument(:bar)
-      assert_equal 1 , @method.has_argument(:foo)
+      assert_equal 1 , @method.arguments_type.variable_index(:bar)
+      assert_equal 2 , @method.arguments_type.variable_index(:foo)
     end
 
     def test_add_arg
-      @method.add_argument(:foo2 , :Object)
-      assert_equal 3 , @method.arguments_length
-      assert_equal :foo2 , @method.argument_name(2)
-      assert_equal :Object , @method.argument_type(2)
+      @method.arguments_type.send( :private_add_instance_variable, :foo2 , :Object)
+      assert_equal 4 , @method.arguments_type.get_length
+      assert_equal :foo2 , @method.arguments_type.name_at(3)
+      assert_equal :Object , @method.arguments_type.type_at(3)
     end
 
     def test_get_arg_name1
-      index = @method.has_argument(:bar)
-      assert_equal 0 , index
-      assert_equal :bar , @method.argument_name(index)
+      index = @method.arguments_type.variable_index(:bar)
+      assert_equal 1 , index
+      assert_equal :bar , @method.arguments_type.name_at(index)
     end
     def test_get_arg_type1
-      index = @method.has_argument(:bar)
-      assert_equal :Integer , @method.argument_type(index)
+      index = @method.arguments_type.variable_index(:bar)
+      assert_equal :Integer , @method.arguments_type.type_at(index)
     end
     def test_get_arg_name2
-      index = @method.has_argument(:foo)
-      assert_equal 1 , index
-      assert_equal :foo , @method.argument_name(index)
+      index = @method.arguments_type.variable_index(:foo)
+      assert_equal 2 , index
+      assert_equal :foo , @method.arguments_type.name_at(index)
     end
     def test_get_arg_type2
-      index = @method.has_argument(:foo)
-      assert_equal :Type , @method.argument_type(index)
+      index = @method.arguments_type.variable_index(:foo)
+      assert_equal :Type , @method.arguments_type.type_at(index)
     end
 
     def test_local1
diff --git a/test/vool/compilers/test_method_compiler.rb b/test/vool/compilers/test_method_compiler.rb
index b252f1f0..0991eead 100644
--- a/test/vool/compilers/test_method_compiler.rb
+++ b/test/vool/compilers/test_method_compiler.rb
@@ -54,8 +54,8 @@ module Vool
       VoolCompiler.ruby_to_vool in_Test("def meth; @ivar = 5; @ibar = 4;end")
       test = Parfait.object_space.get_class_by_name(:Test)
       method = test.instance_type.get_method(:meth)
-      assert_equal 2, method.for_type.variable_index(:ivar)
-      assert_equal 3, method.for_type.variable_index(:ibar)
+      assert_equal 1, method.for_type.variable_index(:ivar)
+      assert_equal 2, method.for_type.variable_index(:ibar)
     end
 
     def test_vool_method_has_one_local
@@ -63,7 +63,8 @@ module Vool
       test = Parfait.object_space.get_class_by_name(:Test)
       method = test.get_method(:meth)
       assert_equal 3 , method.frame_type.instance_length
-      assert_equal 2 , method.frame_type.variable_index(:local)
+      assert_equal 1 , method.frame_type.variable_index(:local)
+      assert_equal 2 , method.frame_type.variable_index(:a)
     end
 
     def test_typed_method_has_one_local
@@ -71,7 +72,7 @@ module Vool
       test = Parfait.object_space.get_class_by_name(:Test)
       method = test.instance_type.get_method(:meth)
       assert_equal 3 , method.frame_type.instance_length
-      assert_equal 2 , method.frame_type.variable_index(:local)
+      assert_equal 1 , method.frame_type.variable_index(:local)
     end
 
   end