diff --git a/tests/chunks/consumer.t.cpp b/tests/chunks/consumer.t.cpp
index 205cfb3..e5a584f 100644
--- a/tests/chunks/consumer.t.cpp
+++ b/tests/chunks/consumer.t.cpp
@@ -39,9 +39,7 @@
 #include <boost/test/output_test_stream.hpp>
 #endif
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 using namespace ndn::tests;
 using boost::test_tools::output_test_stream;
@@ -175,6 +173,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestConsumer
 BOOST_AUTO_TEST_SUITE_END() // Chunks
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests
diff --git a/tests/chunks/discover-version.t.cpp b/tests/chunks/discover-version.t.cpp
index 79315cc..7d18886 100644
--- a/tests/chunks/discover-version.t.cpp
+++ b/tests/chunks/discover-version.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2016-2020, Regents of the University of California,
+ * Copyright (c) 2016-2022, Regents of the University of California,
  *                          Colorado State University,
  *                          University Pierre & Marie Curie, Sorbonne University.
  *
@@ -32,9 +32,7 @@
 #include <ndn-cxx/metadata-object.hpp>
 #include <ndn-cxx/util/dummy-client-face.hpp>
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 using namespace ndn::tests;
 
@@ -215,6 +213,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestDiscoverVersion
 BOOST_AUTO_TEST_SUITE_END() // Chunks
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests
diff --git a/tests/chunks/pipeline-interests-aimd.t.cpp b/tests/chunks/pipeline-interests-aimd.t.cpp
index feed933..0946021 100644
--- a/tests/chunks/pipeline-interests-aimd.t.cpp
+++ b/tests/chunks/pipeline-interests-aimd.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2016-2020, Regents of the University of California,
+ * Copyright (c) 2016-2022, Regents of the University of California,
  *                          Colorado State University,
  *                          University Pierre & Marie Curie, Sorbonne University.
  *
@@ -29,17 +29,14 @@
 
 #include "pipeline-interests-fixture.hpp"
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 using namespace ndn::tests;
 
 class PipelineInterestAimdFixture : public PipelineInterestsFixture
 {
-public:
+protected:
   PipelineInterestAimdFixture()
-    : rttEstimator(makeRttEstimatorOptions())
   {
     opt.isQuiet = true;
     createPipeline();
@@ -70,7 +67,7 @@
 
 protected:
   Options opt;
-  RttEstimatorWithStats rttEstimator;
+  RttEstimatorWithStats rttEstimator{makeRttEstimatorOptions()};
   PipelineInterestsAdaptive* pipeline;
   static constexpr double MARGIN = 0.001;
 };
@@ -596,6 +593,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestPipelineInterestsAimd
 BOOST_AUTO_TEST_SUITE_END() // Chunks
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests
diff --git a/tests/chunks/pipeline-interests-cubic.t.cpp b/tests/chunks/pipeline-interests-cubic.t.cpp
index fc53343..9934d9f 100644
--- a/tests/chunks/pipeline-interests-cubic.t.cpp
+++ b/tests/chunks/pipeline-interests-cubic.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2016-2020, Regents of the University of California,
+ * Copyright (c) 2016-2022, Regents of the University of California,
  *                          Colorado State University,
  *                          University Pierre & Marie Curie, Sorbonne University.
  *
@@ -29,17 +29,14 @@
 
 #include "pipeline-interests-fixture.hpp"
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 using namespace ndn::tests;
 
 class PipelineInterestCubicFixture : public PipelineInterestsFixture
 {
-public:
+protected:
   PipelineInterestCubicFixture()
-    : rttEstimator(makeRttEstimatorOptions())
   {
     opt.isQuiet = true;
     createPipeline();
@@ -70,7 +67,7 @@
 
 protected:
   Options opt;
-  RttEstimatorWithStats rttEstimator;
+  RttEstimatorWithStats rttEstimator{makeRttEstimatorOptions()};
   PipelineInterestsCubic* pipeline;
   static constexpr double MARGIN = 0.001;
 };
@@ -562,6 +559,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestPipelineInterestsCubic
 BOOST_AUTO_TEST_SUITE_END() // Chunks
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests
diff --git a/tests/chunks/pipeline-interests-fixed.t.cpp b/tests/chunks/pipeline-interests-fixed.t.cpp
index 872fe4e..b4f9723 100644
--- a/tests/chunks/pipeline-interests-fixed.t.cpp
+++ b/tests/chunks/pipeline-interests-fixed.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2016-2020, Regents of the University of California,
+ * Copyright (c) 2016-2022, Regents of the University of California,
  *                          Colorado State University,
  *                          University Pierre & Marie Curie, Sorbonne University.
  *
@@ -29,9 +29,7 @@
 
 #include "pipeline-interests-fixture.hpp"
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 class PipelineInterestFixedFixture : public PipelineInterestsFixture
 {
@@ -298,6 +296,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestPipelineInterests
 BOOST_AUTO_TEST_SUITE_END() // Chunks
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests
diff --git a/tests/chunks/pipeline-interests-fixture.hpp b/tests/chunks/pipeline-interests-fixture.hpp
index 643047a..ddfc82b 100644
--- a/tests/chunks/pipeline-interests-fixture.hpp
+++ b/tests/chunks/pipeline-interests-fixture.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2016-2020, Regents of the University of California,
+ * Copyright (c) 2016-2022, Regents of the University of California,
  *                          Colorado State University,
  *                          University Pierre & Marie Curie, Sorbonne University.
  *
@@ -36,9 +36,7 @@
 
 #include <ndn-cxx/util/dummy-client-face.hpp>
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 using namespace ndn::tests;
 
@@ -88,8 +86,6 @@
   unique_ptr<PipelineInterests> m_pipeline;
 };
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests
 
 #endif // NDN_TOOLS_TESTS_CHUNKS_PIPELINE_INTERESTS_FIXTURE_HPP
diff --git a/tests/chunks/producer.t.cpp b/tests/chunks/producer.t.cpp
index ef53422..a4a280b 100644
--- a/tests/chunks/producer.t.cpp
+++ b/tests/chunks/producer.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2016-2021,  Regents of the University of California,
+ * Copyright (c) 2016-2022,  Regents of the University of California,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University.
  *
@@ -37,9 +37,7 @@
 #include <cmath>
 #include <sstream>
 
-namespace ndn {
-namespace chunks {
-namespace tests {
+namespace ndn::chunks::tests {
 
 using namespace ndn::tests;
 
@@ -222,6 +220,4 @@
 BOOST_AUTO_TEST_SUITE_END() // TestProducer
 BOOST_AUTO_TEST_SUITE_END() // Chunks
 
-} // namespace tests
-} // namespace chunks
-} // namespace ndn
+} // namespace ndn::chunks::tests