diff --git a/src/internet-stack/arp-l3-protocol.h b/src/internet-stack/arp-l3-protocol.h
index 7f0294e9f..7bdf7322e 100644
--- a/src/internet-stack/arp-l3-protocol.h
+++ b/src/internet-stack/arp-l3-protocol.h
@@ -84,6 +84,8 @@ protected:
   virtual void NotifyNewAggregate ();
 private:
   typedef std::list<Ptr<ArpCache> > CacheList;
+  ArpL3Protocol (const ArpL3Protocol &o);
+  ArpL3Protocol &operator = (const ArpL3Protocol &o);
   Ptr<ArpCache> FindCache (Ptr<NetDevice> device);
   void SendArpRequest (Ptr<const ArpCache>cache, Ipv4Address to);
   void SendArpReply (Ptr<const ArpCache> cache, Ipv4Address myIp, Ipv4Address toIp, Address toMac);