diff --git a/apps/ndn-consumer-window.h b/apps/ndn-consumer-window.h
index e89d0a7..42ee006 100644
--- a/apps/ndn-consumer-window.h
+++ b/apps/ndn-consumer-window.h
@@ -50,11 +50,10 @@
   // OnInterest (const Ptr<const Interest> &interest);
 
   virtual void
-  OnNack (const Ptr<const Interest> &interest, Ptr<Packet> payload);
+  OnNack (Ptr<const Interest> interest);
 
   virtual void
-  OnContentObject (const Ptr<const ContentObject> &contentObject,
-                   Ptr<Packet> payload);
+  OnContentObject (Ptr<const ContentObject> contentObject);
 
   virtual void
   OnTimeout (uint32_t sequenceNumber);