diff --git a/src/util/scheduler.cpp b/src/util/scheduler.cpp
index 998728f..c2f5564 100644
--- a/src/util/scheduler.cpp
+++ b/src/util/scheduler.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2014 Regents of the University of California.
+ * Copyright (c) 2013-2015 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -24,6 +24,8 @@
 #include "scheduler.hpp"
 
 namespace ndn {
+namespace util {
+namespace scheduler {
 
 struct EventIdImpl
 {
@@ -195,4 +197,6 @@
 }
 
 
+} // namespace scheduler
+} // namespace util
 } // namespace ndn