diff --git a/utils/tracers/ndn-l3-rate-tracer.h b/utils/tracers/ndn-l3-rate-tracer.h
index 9df79b1..d2f965b 100644
--- a/utils/tracers/ndn-l3-rate-tracer.h
+++ b/utils/tracers/ndn-l3-rate-tracer.h
@@ -144,13 +144,13 @@
   DropNacks (Ptr<const Interest>, Ptr<const Face>);
 
   virtual void
-  OutData  (Ptr<const ContentObject>, bool fromCache, Ptr<const Face>);
+  OutData  (Ptr<const Data>, bool fromCache, Ptr<const Face>);
 
   virtual void
-  InData   (Ptr<const ContentObject>, Ptr<const Face>);
+  InData   (Ptr<const Data>, Ptr<const Face>);
 
   virtual void
-  DropData (Ptr<const ContentObject>, Ptr<const Face>);
+  DropData (Ptr<const Data>, Ptr<const Face>);
 
   virtual void
   SatisfiedInterests (Ptr<const pit::Entry>);