diff --git a/tests/benchmarks/encoding-bench.cpp b/tests/benchmarks/encoding-bench.cpp
index 1adb452..a3e0b5e 100644
--- a/tests/benchmarks/encoding-bench.cpp
+++ b/tests/benchmarks/encoding-bench.cpp
@@ -30,11 +30,7 @@
 
 #include <iostream>
 
-namespace ndn {
-namespace tlv {
-namespace tests {
-
-using namespace ndn::tests;
+namespace ndn::tests {
 
 template<size_t WIRE_SIZE>
 struct ReadVarNumberTest;
@@ -112,7 +108,7 @@
     uint64_t number = 0;
     for (int i = 0; i < N_ITERATIONS; ++i) {
       const uint8_t* begin2 = begin; // make a copy because readVarNumber increments the pointer
-      nOks += readVarNumber(begin2, end, number);
+      nOks += tlv::readVarNumber(begin2, end, number);
       nCorrects += number == Test::VALUE;
       // use the number and the return value, so compiler won't optimize out their computation
     }
@@ -124,6 +120,4 @@
             << " " << d << std::endl;
 }
 
-} // namespace tests
-} // namespace tlv
-} // namespace ndn
+} // namespace ndn::tests
diff --git a/tests/benchmarks/scheduler-bench.cpp b/tests/benchmarks/scheduler-bench.cpp
index 8897920..46af278 100644
--- a/tests/benchmarks/scheduler-bench.cpp
+++ b/tests/benchmarks/scheduler-bench.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2023 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -28,11 +28,7 @@
 #include <boost/asio/io_service.hpp>
 #include <iostream>
 
-namespace ndn {
-namespace scheduler {
-namespace tests {
-
-using namespace ndn::tests;
+namespace ndn::tests {
 
 BOOST_AUTO_TEST_CASE(ScheduleCancel)
 {
@@ -40,7 +36,7 @@
   Scheduler sched(io);
 
   const size_t nEvents = 1000000;
-  std::vector<EventId> eventIds(nEvents);
+  std::vector<scheduler::EventId> eventIds(nEvents);
 
   auto d1 = timedExecute([&] {
     for (size_t i = 0; i < nEvents; ++i) {
@@ -67,8 +63,8 @@
   size_t nExpired = 0;
 
   // Events should expire at t1, but execution finishes at t2. The difference is the overhead.
-  time::steady_clock::TimePoint t1 = time::steady_clock::now() + 5_s;
-  time::steady_clock::TimePoint t2;
+  time::steady_clock::time_point t1 = time::steady_clock::now() + 5_s;
+  time::steady_clock::time_point t2;
   // +1ms ensures this extra event is executed last. In case the overhead is less than 1ms,
   // it will be reported as 1ms.
   sched.schedule(t1 - time::steady_clock::now() + 1_ms, [&] {
@@ -86,6 +82,4 @@
   std::cout << "execute " << nEvents << " events: " << (t2 - t1) << std::endl;
 }
 
-} // namespace tests
-} // namespace scheduler
-} // namespace ndn
+} // namespace ndn::tests
diff --git a/tests/benchmarks/timed-execute.hpp b/tests/benchmarks/timed-execute.hpp
index b33873d..7ce5a82 100644
--- a/tests/benchmarks/timed-execute.hpp
+++ b/tests/benchmarks/timed-execute.hpp
@@ -24,8 +24,7 @@
 
 #include "ndn-cxx/util/time.hpp"
 
-namespace ndn {
-namespace tests {
+namespace ndn::tests {
 
 template<typename F>
 time::nanoseconds
@@ -37,7 +36,6 @@
   return after - before;
 }
 
-} // namespace tests
-} // namespace ndn
+} // namespace ndn::tests
 
 #endif // NDN_CXX_TESTS_BENCHMARKS_TIMED_EXECUTE_HPP