diff --git a/utils/tracers/ndn-l3-tracer.hpp b/utils/tracers/ndn-l3-tracer.hpp
index f11e317..a938113 100644
--- a/utils/tracers/ndn-l3-tracer.hpp
+++ b/utils/tracers/ndn-l3-tracer.hpp
@@ -26,6 +26,12 @@
 #include "ns3/ptr.h"
 #include "ns3/simple-ref-count.h"
 
+namespace nfd {
+namespace pit {
+class Entry;
+} // namespace pit
+} // namespace nfd
+
 namespace ns3 {
 
 class Node;
@@ -88,11 +94,11 @@
   virtual void
   InData(const Data&, const Face&) = 0;
 
-  // virtual void
-  // SatisfiedInterests(Ptr<const pit::Entry>) = 0;
+  virtual void
+  SatisfiedInterests(const nfd::pit::Entry&, const Face&, const Data&) = 0;
 
-  // virtual void
-  // TimedOutInterests(Ptr<const pit::Entry>) = 0;
+  virtual void
+  TimedOutInterests(const nfd::pit::Entry&) = 0;
 
 protected:
   std::string m_node;
@@ -106,21 +112,21 @@
       m_outInterests = 0;
       m_inData = 0;
       m_outData = 0;
-      // m_satisfiedInterests = 0;
-      // m_timedOutInterests = 0;
+      m_satisfiedInterests = 0;
+      m_timedOutInterests = 0;
 
-      // m_outSatisfiedInterests = 0;
-      // m_outTimedOutInterests = 0;
+      m_outSatisfiedInterests = 0;
+      m_outTimedOutInterests = 0;
     }
 
     double m_inInterests;
     double m_outInterests;
     double m_inData;
     double m_outData;
-    // double m_satisfiedInterests;
-    // double m_timedOutInterests;
-    // double m_outSatisfiedInterests;
-    // double m_outTimedOutInterests;
+    double m_satisfiedInterests;
+    double m_timedOutInterests;
+    double m_outSatisfiedInterests;
+    double m_outTimedOutInterests;
   };
 };