--- a/examples/stats/wifi-example-apps.cc	Thu Dec 04 12:14:46 2014 -0800
+++ b/examples/stats/wifi-example-apps.cc	Fri Oct 03 02:24:42 2014 -0700
@@ -66,7 +66,8 @@
                    MakePointerAccessor (&Sender::m_interval),
                    MakePointerChecker <RandomVariableStream>())
     .AddTraceSource ("Tx", "A new packet is created and is sent",
-                     MakeTraceSourceAccessor (&Sender::m_txTrace))
+                     MakeTraceSourceAccessor (&Sender::m_txTrace),
+                     "ns3::Packet::TracedCallback")
   ;
   return tid;
 }