diff --git a/lib/register/boot.rb b/lib/register/boot.rb
index f5f8a9bb..bba54b77 100644
--- a/lib/register/boot.rb
+++ b/lib/register/boot.rb
@@ -129,7 +129,7 @@ module Register
                       :super_class_name => :Word},
           :Dictionary => {:keys => :List , :values => :List  } ,
           :TypedMethod => {:name => :Word, :source => :Object, :instructions => :Object, :binary => :Object,
-                      :arguments => :List , :for_class => :Class, :locals => :List  } ,
+                      :arguments => :Type , :for_type => :Type, :locals => :Type } ,
           :Value => {},
           :Variable => {:value_type => :Class, :name => :Word , :value => :Object}
         }
@@ -144,26 +144,27 @@ module Register
       # very fiddly chicken 'n egg problem. Functions need to be in the right order, and in fact we
       # have to define some dummies, just for the others to compile
       # TODO go through the virtual parfait layer and adjust function names to what they really are
-      @space.get_class_by_name(:Space).add_instance_method Builtin::Space.send(:main, nil)
+      space = @space.get_class_by_name(:Space)
+      space.instance_type.add_instance_method Builtin::Space.send(:main, nil)
 
       obj = @space.get_class_by_name(:Object)
       [ :get_internal_word , :set_internal_word ].each do |f|
-        obj.add_instance_method Builtin::Object.send(f , nil)
+        obj.instance_type.add_instance_method Builtin::Object.send(f , nil)
       end
       obj = @space.get_class_by_name(:Kernel)
       # create __init__ main first, __init__ calls it
       [:exit , :__init__ ].each do |f|
-        obj.add_instance_method Builtin::Kernel.send(f , nil)
+        obj.instance_type.add_instance_method Builtin::Kernel.send(f , nil)
       end
 
       obj = @space.get_class_by_name(:Word)
       [:putstring , :get_internal_byte , :set_internal_byte ].each do |f|
-        obj.add_instance_method Builtin::Word.send(f , nil)
+        obj.instance_type.add_instance_method Builtin::Word.send(f , nil)
       end
 
       obj = @space.get_class_by_name(:Integer)
       [ :putint, :mod4, :div10].each do |f|   #mod4 is just a forward declaration
-        obj.add_instance_method Builtin::Integer.send(f , nil)
+        obj.instance_type.add_instance_method Builtin::Integer.send(f , nil)
       end
     end
   end
diff --git a/lib/register/builtin/kernel.rb b/lib/register/builtin/kernel.rb
index 14c412a2..cfb43505 100644
--- a/lib/register/builtin/kernel.rb
+++ b/lib/register/builtin/kernel.rb
@@ -22,7 +22,7 @@ module Register
           compiler.add_code Register.get_slot( source , space_reg , message_ind , :message)
           # And store the space as the new self (so the call can move it back as self)
           compiler.add_code Register.set_slot( source, space_reg , :message , :receiver)
-          exit_label = Label.new("_exit_label" , "#{compiler.clazz.name}.#{compiler.method.name}" )
+          exit_label = Label.new("_exit_label" , "#{compiler.type.object_class.name}.#{compiler.method.name}" )
           ret_tmp = compiler.use_reg(:Label)
           compiler.add_code Register::LoadConstant.new(source, exit_label , ret_tmp)
           compiler.add_code Register.set_slot(source, ret_tmp , :message , :return_address)
diff --git a/lib/register/instructions/function_call.rb b/lib/register/instructions/function_call.rb
index d86d6c64..663fc10e 100644
--- a/lib/register/instructions/function_call.rb
+++ b/lib/register/instructions/function_call.rb
@@ -15,9 +15,9 @@ module Register
     end
   end
 
-  def self.issue_call compiler , callee
+  def self.issue_call( compiler , callee )
     source = "_issue_call(#{callee.name})"
-    return_label = Label.new("_return_label" , "#{compiler.clazz.name}.#{compiler.method.name}" )
+    return_label = Label.new("_return_label" , "#{compiler.type.object_class.name}.#{compiler.method.name}" )
     ret_tmp = compiler.use_reg(:Label)
     compiler.add_code Register::LoadConstant.new(source, return_label , ret_tmp)
     compiler.add_code Register.set_slot(source, ret_tmp , :new_message , :return_address)