--- a/src/devices/wifi/wifi-mac-trailer.h	Mon Mar 17 12:12:17 2008 -0700
+++ b/src/devices/wifi/wifi-mac-trailer.h	Mon Mar 17 13:12:17 2008 -0700
@@ -31,12 +31,14 @@
   WifiMacTrailer ();
   ~WifiMacTrailer ();
 
+  static TypeId GetTypeId (void);
+  virtual TypeId GetInstanceTypeId (void) const;
   static uint32_t GetUid (void);
   std::string GetName (void) const;
   void Print (std::ostream &os) const;
-  uint32_t GetSerializedSize (void) const;
-  void Serialize (Buffer::Iterator start) const;
-  uint32_t Deserialize (Buffer::Iterator start);
+  virtual uint32_t GetSerializedSize (void) const;
+  virtual void Serialize (Buffer::Iterator start) const;
+  virtual uint32_t Deserialize (Buffer::Iterator start);
 };
 
 } // namespace ns3