diff --git a/lib/parfait/binary_code.rb b/lib/parfait/binary_code.rb
index 6779be4c..d85a8a5e 100644
--- a/lib/parfait/binary_code.rb
+++ b/lib/parfait/binary_code.rb
@@ -17,13 +17,18 @@ module Parfait
     end
     def extend_to(total_size)
       if total_size > self.data_length
-        @next = BinaryCode.new(1) unless @next
+        unless @next
+          @next = BinaryCode.new(1)
+          #puts "extending #{total_size - data_length} in #{self}"
+          Risc::Position.reset(self) if Risc::Position.set?(self)
+        end
         @next.extend_to(total_size - data_length)
       end
     end
     def to_s
-      "BinaryCode #{}"
+      "BinaryCode #{Risc::Position.set?(self) ? Risc::Position.get(self): self.object_id.to_s(16)}"
     end
+
     def each_word
       index = 1
       while( index <= data_length)
diff --git a/lib/risc/position.rb b/lib/risc/position.rb
index 701b38e4..c87123e0 100644
--- a/lib/risc/position.rb
+++ b/lib/risc/position.rb
@@ -66,6 +66,13 @@ module Risc
       pos
     end
 
+    # set to the same position as before, thus triggering whatever code that propagates
+    # position _must have been set, otherwise raises
+    def self.reset(obj)
+      old = self.get(obj)
+      old.reset_to( old.at )
+    end
+
     def self.set( object , pos , extra = nil)
       # resetting of position used to be error, but since relink and dynamic instruction size it is ok.
       # in measures (of 32)
@@ -92,6 +99,7 @@ module Risc
       end
     end
   end
+
   # handle event propagation
   class IPosition < Position
     attr_reader :instruction , :binary
@@ -131,5 +139,10 @@ module Risc
       return unless code.next
       Position.set(code.next , at + code.padded_length, method)
     end
+    def reset_to(pos)
+      super(pos)
+      #puts "Reset (#{changed}) #{instruction}"
+      init(pos)
+    end
   end
 end
diff --git a/test/risc/test_position2.rb b/test/risc/test_position2.rb
index 06c3d280..db6e546f 100644
--- a/test/risc/test_position2.rb
+++ b/test/risc/test_position2.rb
@@ -29,10 +29,15 @@ module Risc
       Position.set( @label , 0 , @binary)
       assert_equal 0 , Position.get(@label.next).at
     end
-    def test_bin_propagates
+    def test_bin_propagates_existing
       @binary.extend_to(16)
       Position.set( @binary , 0 , Parfait.object_space.get_main)
       assert_equal @binary.padded_length , Position.get(@binary.next).at
     end
+    def test_bin_propagates_after
+      Position.set( @binary , 0 , Parfait.object_space.get_main)
+      @binary.extend_to(16)
+      assert_equal @binary.padded_length , Position.get(@binary.next).at
+    end
   end
 end