diff --git a/src/util/notification-subscriber.cpp b/src/util/notification-subscriber.cpp
index 56dee40..66ffd8c 100644
--- a/src/util/notification-subscriber.cpp
+++ b/src/util/notification-subscriber.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2014-2016 Regents of the University of California,
+/*
+ * Copyright (c) 2014-2018 Regents of the University of California,
  *                         Arizona Board of Regents,
  *                         Colorado State University,
  *                         University Pierre & Marie Curie, Sorbonne University,
@@ -28,6 +28,8 @@
 #include "notification-subscriber.hpp"
 #include "random.hpp"
 
+#include <cmath>
+
 namespace ndn {
 namespace util {
 
@@ -186,8 +188,8 @@
 
   m_lastNackSequenceNo = nackSequenceNo;
 
-  return time::milliseconds(static_cast<uint32_t>(pow(2, m_attempts) * 100 +
-                                                  random::generateWord32() % 100));
+  return time::milliseconds(static_cast<time::milliseconds::rep>(std::pow(2, m_attempts) * 100 +
+                                                                 random::generateWord32() % 100));
 }
 
 } // namespace util