diff --git a/lib/parfait/type.rb b/lib/parfait/type.rb
index f31e2c62..2709694c 100644
--- a/lib/parfait/type.rb
+++ b/lib/parfait/type.rb
@@ -68,7 +68,17 @@ module Parfait
     end
 
     def to_s
-      "#{class_name}-#{@names.inspect}"
+      str = "#{class_name}-["
+      first = false
+      @names.each do |name|
+        unless(first)
+          first = true
+          str += ":#{name}"
+        else
+          str += ", :#{name}"
+        end
+      end
+      str + "]"
     end
 
     def method_names
diff --git a/lib/risc/register_value.rb b/lib/risc/register_value.rb
index 62a33fab..02d9ce97 100644
--- a/lib/risc/register_value.rb
+++ b/lib/risc/register_value.rb
@@ -66,7 +66,7 @@ module Risc
     end
 
     def to_s
-      s = "#{symbol}:#{type}"
+      s = "#{symbol}:#{type&.class_name}"
       s += ":#{extra}" unless extra.empty?
       s
     end
diff --git a/lib/vool/yield_statement.rb b/lib/vool/yield_statement.rb
index 968fa491..d1a6c995 100644
--- a/lib/vool/yield_statement.rb
+++ b/lib/vool/yield_statement.rb
@@ -64,7 +64,7 @@ module Vool
     # to call the block (that we know now to be the last arg),
     # we do a message setup, arg transfer and the a arg_yield (which is similar to dynamic_call)
     def yield_arg_block(compiler)
-      arg_index = compiler.get_method.arguments_type.get_length
+      arg_index = compiler.get_method.arguments_type.get_length - 1
       setup  = Mom::MessageSetup.new( arg_index )
       mom_receive = @receiver.slot_definition(compiler)
       arg_target = [:message , :next_message , :arguments]
diff --git a/test/vool/test_yield_statement.rb b/test/vool/test_yield_statement.rb
index 11a024e4..e329803e 100644
--- a/test/vool/test_yield_statement.rb
+++ b/test/vool/test_yield_statement.rb
@@ -35,7 +35,7 @@ module Vool
     end
     def test_setup
       assert_equal MessageSetup, @ins.next(2).class
-      assert_equal 3, @ins.next(2).method_source
+      assert_equal 2, @ins.next(2).method_source
     end
     def test_transfer
       assert_equal ArgumentTransfer, @ins.next(3).class
@@ -53,7 +53,7 @@ module Vool
     end
     def test_yield
       assert_equal BlockYield, @ins.next(4).class
-      assert_equal 3, @ins.next(4).arg_index
+      assert_equal 2, @ins.next(4).arg_index
     end
   end
 end