--- a/src/internet-node/arp-ipv4-interface.h	Tue Aug 28 14:32:44 2007 +0200
+++ b/src/internet-node/arp-ipv4-interface.h	Tue Aug 28 14:33:53 2007 +0200
@@ -43,7 +43,7 @@
   virtual ~ArpIpv4Interface ();
 
 protected:
-  virtual Ptr<TraceResolver> GetTraceResolver (void);
+  virtual Ptr<TraceResolver> GetTraceResolver (void) const;
 private:
   virtual void SendTo (Packet p, Ipv4Address dest);
   Ptr<Node> m_node;