diff --git a/utils/tracers/ndn-cs-tracer.h b/utils/tracers/ndn-cs-tracer.h
index b52de9c..ff5fc89 100644
--- a/utils/tracers/ndn-cs-tracer.h
+++ b/utils/tracers/ndn-cs-tracer.h
@@ -39,8 +39,8 @@
 
 namespace ndn {
 
-class InterestHeader;
-class ContentObjectHeader;
+class Interest;
+class ContentObject;
 
 namespace cs {
 
@@ -117,10 +117,10 @@
   Connect ();
 
   void 
-  CacheHits (Ptr<const InterestHeader>, Ptr<const ContentObjectHeader>);
+  CacheHits (Ptr<const Interest>, Ptr<const ContentObject>);
   
   void 
-  CacheMisses (Ptr<const InterestHeader>);
+  CacheMisses (Ptr<const Interest>);
 
 private:
   void