--- a/src/core/model/object-base.cc	Mon Sep 14 13:34:07 2015 -0700
+++ b/src/core/model/object-base.cc	Fri Sep 11 10:52:44 2015 +0200
@@ -53,6 +53,7 @@
   NS_LOG_FUNCTION_NOARGS ();
   TypeId tid = TypeId ("ns3::ObjectBase");
   tid.SetParent (tid);
+  tid.SetGroupName ("Core");
   return tid;
 }