diff --git a/src/security/v2/certificate-storage.cpp b/src/security/v2/certificate-storage.cpp
index d1638d9..a4d482e 100644
--- a/src/security/v2/certificate-storage.cpp
+++ b/src/security/v2/certificate-storage.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).
  *
@@ -26,8 +26,8 @@
 namespace v2 {
 
 CertificateStorage::CertificateStorage()
-  : m_verifiedCertCache(time::hours(1))
-  , m_unverifiedCertCache(time::minutes(5))
+  : m_verifiedCertCache(1_h)
+  , m_unverifiedCertCache(5_min)
 {
 }