--- a/src/core/object-base.h	Sun Mar 16 20:55:18 2008 +0100
+++ b/src/core/object-base.h	Sun Mar 16 20:59:04 2008 +0100
@@ -28,6 +28,7 @@
 {
 public:
   virtual ~ObjectBase ();
+  virtual TypeId GetInstanceTypeId (void) const = 0;
 };
 
 } // namespace ns3