--- a/src/devices/wifi/mac-low.h	Thu Jun 12 11:06:56 2008 -0700
+++ b/src/devices/wifi/mac-low.h	Thu Jun 12 11:14:54 2008 -0700
@@ -339,7 +339,7 @@
    * This method is typically invoked by the lower PHY layer to notify
    * the MAC layer that a packet was unsuccessfully received.
    */
-  void ReceiveError (Ptr<Packet> packet, double rxSnr);
+  void ReceiveError (Ptr<const Packet> packet, double rxSnr);
 private:
   void CancelAllEvents (void);
   uint32_t GetAckSize (void) const;