diff --git a/utils/tracers/ndn-l3-tracer.h b/utils/tracers/ndn-l3-tracer.h
index 13c2630..45eec7d 100644
--- a/utils/tracers/ndn-l3-tracer.h
+++ b/utils/tracers/ndn-l3-tracer.h
@@ -31,10 +31,14 @@
 
 namespace ndn {
 
-class Interest;
 class Face;
+
+class Interest;
 class ContentObject;
 
+typedef Interest InterestHeader;
+typedef ContentObject ContentObjectHeader;
+
 /**
  * @brief Base class for network-layer (incoming/outgoing Interests and Data) tracing of NDN stack
  */