--- a/src/devices/wifi/wifi-phy.h	Thu Jun 12 11:06:56 2008 -0700
+++ b/src/devices/wifi/wifi-phy.h	Thu Jun 12 11:14:54 2008 -0700
@@ -121,7 +121,7 @@
    * arg1: packet received unsuccessfully
    * arg2: snr of packet
    */
-  typedef Callback<void,Ptr<Packet>, double> SyncErrorCallback;
+  typedef Callback<void,Ptr<const Packet>, double> SyncErrorCallback;
 
   static TypeId GetTypeId (void);