diff --git a/model/fw/green-yellow-red.h b/model/fw/green-yellow-red.h
index 4099a12..363d0cb 100644
--- a/model/fw/green-yellow-red.h
+++ b/model/fw/green-yellow-red.h
@@ -49,6 +49,8 @@
   virtual void
   DidReceiveValidNack (Ptr<Face> incomingFace,
                        uint32_t nackCode,
+                       Ptr<const InterestHeader> header,
+                       Ptr<const Packet> origPacket,
                        Ptr<pit::Entry> pitEntry);
 
 private: