diff --git a/apps/ccnx-consumer-window.h b/apps/ccnx-consumer-window.h
index 0c24551..21a9759 100644
--- a/apps/ccnx-consumer-window.h
+++ b/apps/ccnx-consumer-window.h
@@ -47,11 +47,11 @@
   // OnInterest (const Ptr<const CcnxInterestHeader> &interest);
 
   virtual void
-  OnNack (const Ptr<const CcnxInterestHeader> &interest);
+  OnNack (const Ptr<const CcnxInterestHeader> &interest, Ptr<Packet> payload);
 
   virtual void
   OnContentObject (const Ptr<const CcnxContentObjectHeader> &contentObject,
-                   const Ptr<const Packet> &payload);
+                   Ptr<Packet> payload);
 
   virtual void
   OnTimeout (uint32_t sequenceNumber);