diff --git a/src/common/packet.h b/src/common/packet.h
index afd16d5c5..2858f1153 100644
--- a/src/common/packet.h
+++ b/src/common/packet.h
@@ -74,7 +74,8 @@ class PacketPrinter;
  * The performance aspects of the Packet API are discussed in 
  * \ref packetperf
  */
-class Packet : public ObjectBase {
+class Packet 
+{
 public:
   void Ref (void) const;
   void Unref (void) const;
diff --git a/src/core/callback.h b/src/core/callback.h
index 0e0f68798..7a70bb1ce 100644
--- a/src/core/callback.h
+++ b/src/core/callback.h
@@ -71,7 +71,7 @@ struct CallbackTraits<T *>
   }
 };
 
-class CallbackImplBase : public ObjectBase 
+class CallbackImplBase
 {
 public:
   CallbackImplBase ()
diff --git a/src/core/ptr.cc b/src/core/ptr.cc
index 39b7f9554..3474d40ca 100644
--- a/src/core/ptr.cc
+++ b/src/core/ptr.cc
@@ -23,7 +23,6 @@
 #ifdef RUN_SELF_TESTS
 
 #include "test.h"
-#include "object-base.h"
 
 namespace ns3 {
 
@@ -46,7 +45,7 @@ private:
 };
 
 
-class Base : public ObjectBase
+class Base
 {
 public:
   Base ();
diff --git a/src/devices/wifi/wifi-phy.cc b/src/devices/wifi/wifi-phy.cc
index 43e598380..b62cfe230 100644
--- a/src/devices/wifi/wifi-phy.cc
+++ b/src/devices/wifi/wifi-phy.cc
@@ -78,7 +78,7 @@ WifiPhyListener::~WifiPhyListener ()
  *       Phy event class
  ****************************************************************/
 
-class RxEvent : public ObjectBase 
+class RxEvent
 {
 public:
   RxEvent (uint32_t size, WifiMode payloadMode, 
diff --git a/src/simulator/event-impl.h b/src/simulator/event-impl.h
index dcb63e0ff..5526fb0c7 100644
--- a/src/simulator/event-impl.h
+++ b/src/simulator/event-impl.h
@@ -25,7 +25,7 @@
 
 namespace ns3 {
 
-class EventImpl : public ObjectBase 
+class EventImpl
 {
 public:
   EventImpl ();
diff --git a/src/simulator/simulator.cc b/src/simulator/simulator.cc
index 86836684c..bf9a97655 100644
--- a/src/simulator/simulator.cc
+++ b/src/simulator/simulator.cc
@@ -595,7 +595,8 @@ static void cber5 (const int &, const int &, const int &, const int &, const int
 {}
   
 
-class SimulatorTests : public Test, public ObjectBase {
+class SimulatorTests : public Test
+{
 public:
   SimulatorTests ();
   // only here for testing of Ptr<>