diff --git a/tools/ndnsec/cert-gen.cpp b/tools/ndnsec/cert-gen.cpp
index dbab9cb..be0c1e0 100644
--- a/tools/ndnsec/cert-gen.cpp
+++ b/tools/ndnsec/cert-gen.cpp
@@ -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).
  *
@@ -22,6 +22,8 @@
 #include "ndnsec.hpp"
 #include "util.hpp"
 
+#include <boost/tokenizer.hpp>
+
 namespace ndn {
 namespace ndnsec {