diff --git a/tests/daemon/common/config-file.t.cpp b/tests/daemon/common/config-file.t.cpp
index e1c7333..79c8e08 100644
--- a/tests/daemon/common/config-file.t.cpp
+++ b/tests/daemon/common/config-file.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2021,  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,
@@ -31,8 +31,7 @@
 #include <fstream>
 #include <sstream>
 
-namespace nfd {
-namespace tests {
+namespace nfd::tests {
 
 BOOST_AUTO_TEST_SUITE(TestConfigFile)
 
@@ -429,5 +428,4 @@
 
 BOOST_AUTO_TEST_SUITE_END() // TestConfigFile
 
-} // namespace tests
-} // namespace nfd
+} // namespace nfd::tests
diff --git a/tests/daemon/common/counter.t.cpp b/tests/daemon/common/counter.t.cpp
index 60de483..5cffcdb 100644
--- a/tests/daemon/common/counter.t.cpp
+++ b/tests/daemon/common/counter.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  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,
@@ -27,8 +27,7 @@
 
 #include "tests/test-common.hpp"
 
-namespace nfd {
-namespace tests {
+namespace nfd::tests {
 
 BOOST_AUTO_TEST_SUITE(TestCounter)
 
@@ -89,5 +88,4 @@
 
 BOOST_AUTO_TEST_SUITE_END() // TestCounter
 
-} // namespace tests
-} // namespace nfd
+} // namespace nfd::tests
diff --git a/tests/daemon/common/global.t.cpp b/tests/daemon/common/global.t.cpp
index dced382..b738d32 100644
--- a/tests/daemon/common/global.t.cpp
+++ b/tests/daemon/common/global.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  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,
@@ -31,8 +31,7 @@
 
 #include <thread>
 
-namespace nfd {
-namespace tests {
+namespace nfd::tests {
 
 BOOST_FIXTURE_TEST_SUITE(TestGlobal, GlobalIoFixture)
 
@@ -140,5 +139,4 @@
 
 BOOST_AUTO_TEST_SUITE_END() // TestGlobal
 
-} // namespace tests
-} // namespace nfd
+} // namespace nfd::tests
diff --git a/tests/daemon/common/privilege-helper.t.cpp b/tests/daemon/common/privilege-helper.t.cpp
index c670a5f..d519805 100644
--- a/tests/daemon/common/privilege-helper.t.cpp
+++ b/tests/daemon/common/privilege-helper.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2021,  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,
@@ -27,8 +27,7 @@
 
 #include "tests/test-common.hpp"
 
-namespace nfd {
-namespace tests {
+namespace nfd::tests {
 
 BOOST_AUTO_TEST_SUITE(TestPrivilegeHelper)
 
@@ -69,5 +68,4 @@
 
 BOOST_AUTO_TEST_SUITE_END() // TestPrivilegeHelper
 
-} // namespace tests
-} // namespace nfd
+} // namespace nfd::tests