diff --git a/tools/ndnsec/util.hpp b/tools/ndnsec/util.hpp
index cb95718..61b6b52 100644
--- a/tools/ndnsec/util.hpp
+++ b/tools/ndnsec/util.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2017 Regents of the University of California.
+ * Copyright (c) 2013-2018 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -33,7 +33,6 @@
 #include <string>
 
 #include <boost/asio.hpp>
-#include <boost/date_time/posix_time/posix_time.hpp>
 #include <boost/exception/all.hpp>
 #include <boost/program_options/options_description.hpp>
 #include <boost/program_options/parsers.hpp>