diff --git a/src/util/dns.cpp b/src/util/dns.cpp
index 0adfbd2..73fd8b1 100644
--- a/src/util/dns.cpp
+++ b/src/util/dns.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2015 Regents of the University of California.
+ * Copyright (c) 2013-2016 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -20,9 +20,11 @@
  */
 
 #include "dns.hpp"
-
 #include "scheduler.hpp"
 
+#include <boost/asio/io_service.hpp>
+#include <boost/asio/ip/udp.hpp>
+
 namespace ndn {
 namespace dns {