diff --git a/src/internet-node/ipv4-l4-demux.cc b/src/internet-node/ipv4-l4-demux.cc
index 3547e239f..2a026de36 100644
--- a/src/internet-node/ipv4-l4-demux.cc
+++ b/src/internet-node/ipv4-l4-demux.cc
@@ -32,12 +32,10 @@ namespace ns3 {
 
 const Iid Ipv4L4Demux::iid ("Ipv4L4Demux");
 
-Ipv4L4Demux::Ipv4L4Demux (Node *node)
+Ipv4L4Demux::Ipv4L4Demux (Ptr<Node> node)
   : NsUnknown (Ipv4L4Demux::iid),
     m_node (node)
-{
-  m_node->Ref ();
-}
+{}
 
 Ipv4L4Demux::~Ipv4L4Demux()
 {}
@@ -51,11 +49,7 @@ Ipv4L4Demux::DoDispose (void)
       (*i)->Unref ();
     }
   m_protocols.clear ();
-  if (m_node != 0)
-    {
-      m_node->Unref ();
-      m_node = 0;
-    }
+  m_node = 0;
   NsUnknown::DoDispose ();
 }
 
diff --git a/src/internet-node/ipv4-l4-demux.h b/src/internet-node/ipv4-l4-demux.h
index 3e70ad9d7..d52ce34b9 100644
--- a/src/internet-node/ipv4-l4-demux.h
+++ b/src/internet-node/ipv4-l4-demux.h
@@ -27,6 +27,7 @@
 
 #include <list>
 #include "ns3/ns-unknown.h"
+#include "ns3/ptr.h"
 
 namespace ns3 {
 
@@ -43,7 +44,7 @@ class Ipv4L4Demux : public NsUnknown
 public:
   static const Iid iid;
   typedef int Ipv4L4ProtocolTraceType;
-  Ipv4L4Demux (Node *node);
+  Ipv4L4Demux (Ptr<Node> node);
   virtual ~Ipv4L4Demux();
 
   /**
@@ -86,7 +87,7 @@ private:
   virtual void DoDispose (void);
   typedef std::list<Ipv4L4Protocol*> L4List_t;
   L4List_t m_protocols;
-  Node *m_node;
+  Ptr<Node> m_node;
 };
 
 } //namespace ns3