diff --git a/core/scheduler.hpp b/core/scheduler.hpp
index b846c64..8c9db68 100644
--- a/core/scheduler.hpp
+++ b/core/scheduler.hpp
@@ -27,22 +27,21 @@
 #define NFD_CORE_SCHEDULER_HPP
 
 #include "common.hpp"
-#include <ndn-cxx/util/scheduler.hpp>
+
+#include "ns3/simulator.h"
 
 namespace nfd {
 namespace scheduler {
 
-using ndn::Scheduler;
-
 /** \class EventId
  *  \brief Opaque type (shared_ptr) representing ID of a scheduled event
  */
-using ndn::EventId;
+typedef std::shared_ptr<ns3::EventId> EventId;
 
 /** \brief schedule an event
  */
 EventId
-schedule(const time::nanoseconds& after, const Scheduler::Event& event);
+schedule(const time::nanoseconds& after, const std::function<void()>& event);
 
 /** \brief cancel a scheduled event
  */