diff --git a/src/security/validity-period.hpp b/src/security/validity-period.hpp
index d09657f..e87c6ec 100644
--- a/src/security/validity-period.hpp
+++ b/src/security/validity-period.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2013-2016 Regents of the University of California.
+/*
+ * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -125,6 +125,8 @@
   mutable Block m_wire;
 };
 
+NDN_CXX_DECLARE_WIRE_ENCODE_INSTANTIATIONS(ValidityPeriod);
+
 std::ostream&
 operator<<(std::ostream& os, const ValidityPeriod& period);