diff --git a/tests/clock-fixture.cpp b/tests/clock-fixture.cpp
index 564f128..f138bda 100644
--- a/tests/clock-fixture.cpp
+++ b/tests/clock-fixture.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020,  Regents of the University of California,
+ * Copyright (c) 2014-2022,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -25,8 +25,7 @@
 
 #include "tests/clock-fixture.hpp"
 
-namespace ndn {
-namespace tests {
+namespace ndn::tests {
 
 ClockFixture::ClockFixture()
   : m_steadyClock(make_shared<time::UnitTestSteadyClock>())
@@ -56,5 +55,4 @@
   }
 }
 
-} // namespace tests
-} // namespace ndn
+} // namespace ndn::tests