diff --git a/lib/risc/register_value.rb b/lib/risc/register_value.rb
index d6354b40..3d1d5664 100644
--- a/lib/risc/register_value.rb
+++ b/lib/risc/register_value.rb
@@ -21,12 +21,10 @@ module Risc
     # for an XX instance
     def initialize( reg , type , extra = {})
       extra = {} unless extra
-      raise "Not Hash #{extra}"  unless extra.is_a?(Hash)
-      type = Parfait.object_space.get_type_by_class_name(type) if type.is_a?(Symbol)
-      raise "No type #{reg}" unless type
-      @type = type
-      @symbol = reg
       @extra = extra
+      @symbol = reg
+      raise "Not Hash #{extra}"  unless extra.is_a?(Hash)
+      known_type(type)
     end
 
     def class_name
@@ -42,6 +40,16 @@ module Risc
       self
     end
 
+    # basically set the type with the given symbol. Symbol is resolved to type
+    # just like in constructor
+    # return self for chaining
+    def known_type( type )
+      type = Parfait.object_space.get_type_by_class_name(type) if type.is_a?(Symbol)
+      raise "No type #{type} for #{self}" unless type
+      @type = type
+      self
+    end
+
     # using the registers type, resolve the slot to an index
     # Using the index and the register, add a SlotToReg to the instruction
     def resolve_and_add(slot , compiler)
diff --git a/test/risc/test_register_slot.rb b/test/risc/test_register_slot.rb
index ef23d0c6..1259479e 100644
--- a/test/risc/test_register_slot.rb
+++ b/test/risc/test_register_slot.rb
@@ -73,26 +73,4 @@ module Risc
       assert_equal :message , inst.array.symbol
     end
   end
-  class TestRegisterSlot4 < MiniTest::Test
-    include HasCompiler
-    def setup
-      Parfait.boot!(Parfait.default_test_options)
-      @compiler = Risc.test_compiler
-      @r0 = RegisterValue.new(:message , :Message).set_compiler(@compiler)
-      @r0[:next_message][:return_address] << @r0
-    end
-    def test_instructions
-      assert_equal SlotToReg ,  @compiler.risc_instructions.next(1).class
-      assert_equal RegToSlot ,  @compiler.risc_instructions.next(2).class
-      assert_equal NilClass ,  @compiler.risc_instructions.next(3).class
-    end
-    def test_slot_to
-      assert_slot_to_reg 1 , :message, 1, :"message.next_message"
-      assert risc(1).register.compiler
-    end
-    def test_reg_to
-      assert_reg_to_slot 2 , :message, :"message.next_message" , 4
-      assert risc(2).register.compiler
-    end
-  end
 end
diff --git a/test/risc/test_register_slot1.rb b/test/risc/test_register_slot1.rb
new file mode 100644
index 00000000..eceea387
--- /dev/null
+++ b/test/risc/test_register_slot1.rb
@@ -0,0 +1,26 @@
+require_relative "../helper"
+
+module Risc
+  class TestRegisterSlot4 < MiniTest::Test
+    include HasCompiler
+    def setup
+      Parfait.boot!(Parfait.default_test_options)
+      @compiler = Risc.test_compiler
+      @r0 = RegisterValue.new(:message , :Message).set_compiler(@compiler)
+      @r0[:next_message][:return_address] << @r0
+    end
+    def test_instructions
+      assert_equal SlotToReg ,  @compiler.risc_instructions.next(1).class
+      assert_equal RegToSlot ,  @compiler.risc_instructions.next(2).class
+      assert_equal NilClass ,  @compiler.risc_instructions.next(3).class
+    end
+    def test_slot_to
+      assert_slot_to_reg 1 , :message, 1, :"message.next_message"
+      assert risc(1).register.compiler
+    end
+    def test_reg_to
+      assert_reg_to_slot 2 , :message, :"message.next_message" , 4
+      assert risc(2).register.compiler
+    end
+  end
+end
diff --git a/test/risc/test_register_value1.rb b/test/risc/test_register_value1.rb
index 5a5e20d7..5fd0e15d 100644
--- a/test/risc/test_register_value1.rb
+++ b/test/risc/test_register_value1.rb
@@ -45,5 +45,10 @@ module Risc
       # works with nil as compiler, because extra is used
       assert_equal :Message , @r1.get_new_left(:arguments , nil).type.class_name
     end
+    def test_type_setting
+      reg = @r0.known_type(:Integer)
+      assert_equal Parfait::Type , reg.type.class
+      assert_equal "Integer_Type" , reg.type.name
+    end
   end
 end