diff --git a/tests/unit/util/dummy-client-face.t.cpp b/tests/unit/util/dummy-client-face.t.cpp
index acd6297..b823be2 100644
--- a/tests/unit/util/dummy-client-face.t.cpp
+++ b/tests/unit/util/dummy-client-face.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2018 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -21,9 +21,8 @@
 
 #include "ndn-cxx/util/dummy-client-face.hpp"
 
-#include "tests/boost-test.hpp"
-#include "tests/make-interest-data.hpp"
-#include "tests/unit/identity-management-time-fixture.hpp"
+#include "tests/test-common.hpp"
+#include "tests/unit/io-key-chain-fixture.hpp"
 
 namespace ndn {
 namespace util {
@@ -32,7 +31,7 @@
 using namespace ndn::tests;
 
 BOOST_AUTO_TEST_SUITE(Util)
-BOOST_FIXTURE_TEST_SUITE(TestDummyClientFace, ndn::tests::IdentityManagementTimeFixture)
+BOOST_FIXTURE_TEST_SUITE(TestDummyClientFace, IoKeyChainFixture)
 
 BOOST_AUTO_TEST_CASE(ProcessEventsOverride)
 {
@@ -42,15 +41,15 @@
     BOOST_CHECK_EQUAL(timeout, 200_ms);
   };
 
-  DummyClientFace face(io, {false, false, override});
+  DummyClientFace face(m_io, {false, false, override});
   face.processEvents(200_ms);
   BOOST_CHECK(isOverrideInvoked);
 }
 
 BOOST_AUTO_TEST_CASE(BroadcastLink)
 {
-  DummyClientFace face1(io, m_keyChain, DummyClientFace::Options{true, true});
-  DummyClientFace face2(io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face1(m_io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face2(m_io, m_keyChain, DummyClientFace::Options{true, true});
   face1.linkTo(face2);
 
   int nFace1Interest = 0;
@@ -97,14 +96,14 @@
 
 BOOST_AUTO_TEST_CASE(BroadcastLinkDestroy)
 {
-  DummyClientFace face1(io, m_keyChain, DummyClientFace::Options{true, true});
-  DummyClientFace face2(io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face1(m_io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face2(m_io, m_keyChain, DummyClientFace::Options{true, true});
 
   face1.linkTo(face2);
   face2.unlink();
   BOOST_CHECK(face1.m_bcastLink == nullptr);
 
-  DummyClientFace face3(io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face3(m_io, m_keyChain, DummyClientFace::Options{true, true});
   face1.linkTo(face2);
   face3.linkTo(face1);
   face2.unlink();
@@ -113,10 +112,10 @@
 
 BOOST_AUTO_TEST_CASE(AlreadyLinkException)
 {
-  DummyClientFace face1(io, m_keyChain, DummyClientFace::Options{true, true});
-  DummyClientFace face2(io, m_keyChain, DummyClientFace::Options{true, true});
-  DummyClientFace face3(io, m_keyChain, DummyClientFace::Options{true, true});
-  DummyClientFace face4(io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face1(m_io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face2(m_io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face3(m_io, m_keyChain, DummyClientFace::Options{true, true});
+  DummyClientFace face4(m_io, m_keyChain, DummyClientFace::Options{true, true});
 
   face1.linkTo(face2);
   face3.linkTo(face4);
diff --git a/tests/unit/util/io.t.cpp b/tests/unit/util/io.t.cpp
index 9340279..1ebaf61 100644
--- a/tests/unit/util/io.t.cpp
+++ b/tests/unit/util/io.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2019 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -22,7 +22,7 @@
 #include "ndn-cxx/util/io.hpp"
 
 #include "tests/boost-test.hpp"
-#include "tests/identity-management-fixture.hpp"
+#include "tests/key-chain-fixture.hpp"
 
 #include <boost/filesystem.hpp>
 #include <boost/mpl/vector.hpp>
@@ -100,7 +100,7 @@
 {
 protected:
   FileIoFixture()
-    : filepath(boost::filesystem::path(UNIT_TEST_CONFIG_PATH) / "TestIo")
+    : filepath(boost::filesystem::path(UNIT_TESTS_TMPDIR) / "TestIo")
     , filename(filepath.string())
   {
     boost::filesystem::create_directories(filepath.parent_path());
@@ -327,23 +327,23 @@
 BOOST_AUTO_TEST_SUITE_END() // FileIo
 
 class IdCertFixture : public FileIoFixture
-                    , public IdentityManagementFixture
+                    , public KeyChainFixture
 {
 };
 
 BOOST_FIXTURE_TEST_CASE(IdCert, IdCertFixture)
 {
-  auto identity = addIdentity("/TestIo/IdCert", RsaKeyParams());
+  auto identity = m_keyChain.createIdentity("/TestIo/IdCert", RsaKeyParams());
   const auto& cert = identity.getDefaultKey().getDefaultCertificate();
   io::save(cert, filename);
 
-  auto readCert = io::load<security::v2::Certificate>(filename);
+  auto readCert = io::load<security::Certificate>(filename);
 
   BOOST_REQUIRE(readCert != nullptr);
   BOOST_CHECK_EQUAL(cert.getName(), readCert->getName());
 
   this->writeFile<std::string>("");
-  readCert = io::load<security::v2::Certificate>(filename);
+  readCert = io::load<security::Certificate>(filename);
   BOOST_REQUIRE(readCert == nullptr);
 }
 
diff --git a/tests/unit/util/logging.t.cpp b/tests/unit/util/logging.t.cpp
index 8bbc638..24ae88b 100644
--- a/tests/unit/util/logging.t.cpp
+++ b/tests/unit/util/logging.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2019 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -23,7 +23,7 @@
 #include "ndn-cxx/util/logger.hpp"
 
 #include "tests/boost-test.hpp"
-#include "tests/unit/unit-test-time-fixture.hpp"
+#include "tests/unit/clock-fixture.hpp"
 
 #if BOOST_VERSION >= 105900
 #include <boost/test/tools/output_test_stream.hpp>
@@ -169,14 +169,14 @@
 const time::microseconds LOG_SYSTIME(1468108800311239LL);
 const std::string LOG_SYSTIME_STR("1468108800.311239");
 
-class LoggingFixture : public ndn::tests::UnitTestTimeFixture
+class LoggingFixture : public ndn::tests::ClockFixture
 {
 protected:
   LoggingFixture()
     : m_oldEnabledLevel(Logging::get().getLevels())
     , m_oldDestination(Logging::get().getDestination())
   {
-    this->systemClock->setNow(LOG_SYSTIME);
+    m_systemClock->setNow(LOG_SYSTIME);
     Logging::get().resetLevels();
     Logging::setDestination(os);
   }
diff --git a/tests/unit/util/notification-stream.t.cpp b/tests/unit/util/notification-stream.t.cpp
index ada10c5..2df3014 100644
--- a/tests/unit/util/notification-stream.t.cpp
+++ b/tests/unit/util/notification-stream.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2018 Regents of the University of California,
+ * Copyright (c) 2014-2020 Regents of the University of California,
  *                         Arizona Board of Regents,
  *                         Colorado State University,
  *                         University Pierre & Marie Curie, Sorbonne University,
@@ -29,7 +29,7 @@
 #include "ndn-cxx/util/dummy-client-face.hpp"
 
 #include "tests/boost-test.hpp"
-#include "tests/unit/identity-management-time-fixture.hpp"
+#include "tests/unit/io-key-chain-fixture.hpp"
 #include "tests/unit/util/simple-notification.hpp"
 
 namespace ndn {
@@ -37,13 +37,14 @@
 namespace tests {
 
 BOOST_AUTO_TEST_SUITE(Util)
-BOOST_FIXTURE_TEST_SUITE(TestNotificationStream, ndn::tests::IdentityManagementTimeFixture)
+BOOST_FIXTURE_TEST_SUITE(TestNotificationStream, ndn::tests::IoKeyChainFixture)
 
 BOOST_AUTO_TEST_CASE(Post)
 {
-  DummyClientFace face(io, m_keyChain);
-  util::NotificationStream<SimpleNotification> notificationStream(face,
-    "/localhost/nfd/NotificationStreamTest", m_keyChain);
+  DummyClientFace face(m_io, m_keyChain);
+  NotificationStream<SimpleNotification> notificationStream(face,
+                                                            "/localhost/nfd/NotificationStreamTest",
+                                                            m_keyChain);
 
   SimpleNotification event1("msg1");
   notificationStream.postNotification(event1);
diff --git a/tests/unit/util/notification-subscriber.t.cpp b/tests/unit/util/notification-subscriber.t.cpp
index e3b7aa9..d8f9dfd 100644
--- a/tests/unit/util/notification-subscriber.t.cpp
+++ b/tests/unit/util/notification-subscriber.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) 2014-2020 Regents of the University of California,
  *                         Arizona Board of Regents,
  *                         Colorado State University,
  *                         University Pierre & Marie Curie, Sorbonne University,
@@ -28,9 +28,8 @@
 #include "ndn-cxx/util/notification-subscriber.hpp"
 #include "ndn-cxx/util/dummy-client-face.hpp"
 
-#include "tests/boost-test.hpp"
-#include "tests/make-interest-data.hpp"
-#include "tests/unit/identity-management-time-fixture.hpp"
+#include "tests/test-common.hpp"
+#include "tests/unit/io-key-chain-fixture.hpp"
 #include "tests/unit/util/simple-notification.hpp"
 
 namespace ndn {
@@ -39,12 +38,12 @@
 
 using namespace ndn::tests;
 
-class NotificationSubscriberFixture : public IdentityManagementTimeFixture
+class NotificationSubscriberFixture : public IoKeyChainFixture
 {
 public:
   NotificationSubscriberFixture()
-    : streamPrefix("ndn:/NotificationSubscriberTest")
-    , subscriberFace(io, m_keyChain)
+    : streamPrefix("/NotificationSubscriberTest")
+    , subscriberFace(m_io, m_keyChain)
     , subscriber(subscriberFace, streamPrefix, 1_s)
     , nextSendNotificationNo(0)
   {
diff --git a/tests/unit/util/scheduler.t.cpp b/tests/unit/util/scheduler.t.cpp
index 021c1f0..1bd3860 100644
--- a/tests/unit/util/scheduler.t.cpp
+++ b/tests/unit/util/scheduler.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2019 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -22,7 +22,7 @@
 #include "ndn-cxx/util/scheduler.hpp"
 
 #include "tests/boost-test.hpp"
-#include "tests/unit/unit-test-time-fixture.hpp"
+#include "tests/unit/io-fixture.hpp"
 
 #include <boost/lexical_cast.hpp>
 
@@ -30,16 +30,10 @@
 namespace scheduler {
 namespace tests {
 
-class SchedulerFixture : public ndn::tests::UnitTestTimeFixture
+class SchedulerFixture : public ndn::tests::IoFixture
 {
-public:
-  SchedulerFixture()
-    : scheduler(io)
-  {
-  }
-
-public:
-  Scheduler scheduler;
+protected:
+  Scheduler scheduler{m_io};
 };
 
 BOOST_AUTO_TEST_SUITE(Util)
@@ -201,9 +195,8 @@
 
 BOOST_AUTO_TEST_CASE(CancelAllWithScopedEventId) // Bug 3691
 {
-  Scheduler sched(io);
-  ScopedEventId eid = sched.schedule(10_ms, []{});
-  sched.cancelAllEvents();
+  ScopedEventId eid = scheduler.schedule(10_ms, []{});
+  scheduler.cancelAllEvents();
   eid.cancel(); // should not crash
 
   // avoid "test case [...] did not check any assertions" message from Boost.Test
diff --git a/tests/unit/util/segment-fetcher.t.cpp b/tests/unit/util/segment-fetcher.t.cpp
index 7f63db8..c58c1f9 100644
--- a/tests/unit/util/segment-fetcher.t.cpp
+++ b/tests/unit/util/segment-fetcher.t.cpp
@@ -25,10 +25,9 @@
 #include "ndn-cxx/lp/nack.hpp"
 #include "ndn-cxx/util/dummy-client-face.hpp"
 
-#include "tests/boost-test.hpp"
-#include "tests/make-interest-data.hpp"
+#include "tests/test-common.hpp"
 #include "tests/unit/dummy-validator.hpp"
-#include "tests/unit/identity-management-time-fixture.hpp"
+#include "tests/unit/io-key-chain-fixture.hpp"
 
 #include <set>
 
@@ -38,27 +37,20 @@
 
 using namespace ndn::tests;
 
-class Fixture : public IdentityManagementTimeFixture
+class SegmentFetcherFixture : public IoKeyChainFixture
 {
 public:
-  Fixture()
-    : face(io, m_keyChain)
-  {
-  }
-
   static shared_ptr<Data>
   makeDataSegment(const Name& baseName, uint64_t segment, bool isFinal)
   {
     const uint8_t buffer[] = "Hello, world!";
-
-    auto data = make_shared<Data>(Name(baseName).appendSegment(segment));
-    data->setFreshnessPeriod(1_s);
+    auto data = makeData(Name(baseName).appendSegment(segment));
     data->setContent(buffer, sizeof(buffer));
+    data->setFreshnessPeriod(1_s);
     if (isFinal) {
       data->setFinalBlock(data->getName()[-1]);
     }
-
-    return signData(data);
+    return data;
   }
 
   void
@@ -90,21 +82,20 @@
   }
 
   void
-  nackLastInterest(lp::NackReason nackReason)
+  nackLastInterest(lp::NackReason reason)
   {
     const Interest& lastInterest = face.sentInterests.back();
-    lp::Nack nack = makeNack(lastInterest, nackReason);
-    face.receive(nack);
+    face.receive(makeNack(lastInterest, reason));
     advanceClocks(10_ms);
   }
 
   void
   connectSignals(const shared_ptr<SegmentFetcher>& fetcher)
   {
-    fetcher->onInOrderData.connect(bind(&Fixture::onInOrderData, this, _1));
-    fetcher->onInOrderComplete.connect(bind(&Fixture::onInOrderComplete, this));
-    fetcher->onComplete.connect(bind(&Fixture::onComplete, this, _1));
-    fetcher->onError.connect(bind(&Fixture::onError, this, _1));
+    fetcher->onInOrderData.connect(bind(&SegmentFetcherFixture::onInOrderData, this, _1));
+    fetcher->onInOrderComplete.connect(bind(&SegmentFetcherFixture::onInOrderComplete, this));
+    fetcher->onComplete.connect(bind(&SegmentFetcherFixture::onComplete, this, _1));
+    fetcher->onError.connect(bind(&SegmentFetcherFixture::onError, this, _1));
 
     fetcher->afterSegmentReceived.connect([this] (const auto&) { ++this->nAfterSegmentReceived; });
     fetcher->afterSegmentValidated.connect([this] (const auto &) { ++this->nAfterSegmentValidated; });
@@ -133,7 +124,7 @@
 
       uniqSegmentsSent.insert(interest.getName().get(-1).toSegment());
       if (uniqSegmentsSent.size() == nSegments) {
-        io.stop();
+        m_io.stop();
       }
     }
     else {
@@ -154,7 +145,7 @@
   }
 
 public:
-  DummyClientFace face;
+  DummyClientFace face{m_io, m_keyChain};
   std::set<uint64_t> uniqSegmentsSent;
 
   int nErrors = 0;
@@ -178,7 +169,7 @@
 };
 
 BOOST_AUTO_TEST_SUITE(Util)
-BOOST_FIXTURE_TEST_SUITE(TestSegmentFetcher, Fixture)
+BOOST_FIXTURE_TEST_SUITE(TestSegmentFetcher, SegmentFetcherFixture)
 
 BOOST_AUTO_TEST_CASE(InvalidOptions)
 {
@@ -318,7 +309,7 @@
 
   shared_ptr<SegmentFetcher> fetcher = SegmentFetcher::start(face, Interest("/hello/world"),
                                                              acceptValidator);
-  face.onSendInterest.connect(bind(&Fixture::onInterest, this, _1));
+  face.onSendInterest.connect(bind(&SegmentFetcherFixture::onInterest, this, _1));
   connectSignals(fetcher);
 
   face.processEvents(1_s);
@@ -341,7 +332,7 @@
   sendNackInsteadOfDropping = false;
 
   auto fetcher = SegmentFetcher::start(face, Interest("/hello/world"), acceptValidator, options);
-  face.onSendInterest.connect(bind(&Fixture::onInterest, this, _1));
+  face.onSendInterest.connect(bind(&SegmentFetcherFixture::onInterest, this, _1));
   connectSignals(fetcher);
 
   face.processEvents(1_s);
@@ -366,7 +357,7 @@
 
   shared_ptr<SegmentFetcher> fetcher = SegmentFetcher::start(face, Interest("/hello/world"),
                                                              acceptValidator);
-  face.onSendInterest.connect(bind(&Fixture::onInterest, this, _1));
+  face.onSendInterest.connect(bind(&SegmentFetcherFixture::onInterest, this, _1));
   connectSignals(fetcher);
 
   face.processEvents(1_s);
@@ -390,7 +381,7 @@
   defaultSegmentToSend = 47;
 
   auto fetcher = SegmentFetcher::start(face, Interest("/hello/world"), acceptValidator, options);
-  face.onSendInterest.connect(bind(&Fixture::onInterest, this, _1));
+  face.onSendInterest.connect(bind(&SegmentFetcherFixture::onInterest, this, _1));
   connectSignals(fetcher);
 
   face.processEvents(1_s);
@@ -635,7 +626,7 @@
 
   shared_ptr<SegmentFetcher> fetcher = SegmentFetcher::start(face, Interest("/hello/world"),
                                                              acceptValidator);
-  face.onSendInterest.connect(bind(&Fixture::onInterest, this, _1));
+  face.onSendInterest.connect(bind(&SegmentFetcherFixture::onInterest, this, _1));
   connectSignals(fetcher);
 
   face.processEvents(1_s);
@@ -660,7 +651,7 @@
 
   shared_ptr<SegmentFetcher> fetcher = SegmentFetcher::start(face, Interest("/hello/world"),
                                                              acceptValidator);
-  face.onSendInterest.connect(bind(&Fixture::onInterest, this, _1));
+  face.onSendInterest.connect(bind(&SegmentFetcherFixture::onInterest, this, _1));
   connectSignals(fetcher);
 
   face.processEvents(1_s);
@@ -680,7 +671,7 @@
   segmentsToDropOrNack.push(0);
   sendNackInsteadOfDropping = true;
   nackReason = lp::NackReason::NO_ROUTE;
-  face.onSendInterest.connect(bind(&Fixture::onInterest, this, _1));
+  face.onSendInterest.connect(bind(&SegmentFetcherFixture::onInterest, this, _1));
 
   shared_ptr<SegmentFetcher> fetcher = SegmentFetcher::start(face, Interest("/hello/world"),
                                                              acceptValidator);
diff --git a/tests/unit/util/sqlite3-statement.t.cpp b/tests/unit/util/sqlite3-statement.t.cpp
index c5ee8b6..a78b077 100644
--- a/tests/unit/util/sqlite3-statement.t.cpp
+++ b/tests/unit/util/sqlite3-statement.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2018 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -31,13 +31,13 @@
 namespace util {
 namespace tests {
 
-class Sqlite3StatementTestFixture
+class Sqlite3DbFixture
 {
 public:
-  Sqlite3StatementTestFixture()
-    : m_path(boost::filesystem::path(UNIT_TEST_CONFIG_PATH))
+  Sqlite3DbFixture()
   {
     boost::filesystem::create_directories(m_path);
+
     int result = sqlite3_open_v2((m_path / "sqlite3-statement.db").string().c_str(), &db,
                                  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE,
 #ifdef NDN_CXX_DISABLE_SQLITE3_FS_LOCKING
@@ -52,21 +52,21 @@
     }
   }
 
-  ~Sqlite3StatementTestFixture()
+  ~Sqlite3DbFixture()
   {
     sqlite3_close(db);
     boost::filesystem::remove_all(m_path);
   }
 
-private:
-  boost::filesystem::path m_path;
+protected:
+  sqlite3* db = nullptr;
 
-public:
-  sqlite3* db;
+private:
+  const boost::filesystem::path m_path{UNIT_TESTS_TMPDIR};
 };
 
 BOOST_AUTO_TEST_SUITE(Util)
-BOOST_FIXTURE_TEST_SUITE(TestSqlite3Statement, Sqlite3StatementTestFixture)
+BOOST_FIXTURE_TEST_SUITE(TestSqlite3Statement, Sqlite3DbFixture)
 
 BOOST_AUTO_TEST_CASE(Basic)
 {
diff --git a/tests/unit/util/time-unit-test-clock.t.cpp b/tests/unit/util/time-unit-test-clock.t.cpp
index b65c9f9..f1be623 100644
--- a/tests/unit/util/time-unit-test-clock.t.cpp
+++ b/tests/unit/util/time-unit-test-clock.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2019 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -23,7 +23,7 @@
 #include "ndn-cxx/util/scheduler.hpp"
 
 #include "tests/boost-test.hpp"
-#include "tests/unit/unit-test-time-fixture.hpp"
+#include "tests/unit/io-fixture.hpp"
 
 #include <boost/lexical_cast.hpp>
 #include <thread>
@@ -32,7 +32,7 @@
 namespace tests {
 
 BOOST_AUTO_TEST_SUITE(Util)
-BOOST_FIXTURE_TEST_SUITE(TestTimeUnitTestClock, UnitTestTimeFixture)
+BOOST_FIXTURE_TEST_SUITE(TestTimeUnitTestClock, ClockFixture)
 
 BOOST_AUTO_TEST_CASE(SystemClock)
 {
@@ -43,11 +43,11 @@
   BOOST_CHECK_EQUAL(time::system_clock::now().time_since_epoch(),
                     time::UnitTestClockTraits<time::system_clock>::getDefaultStartTime());
 
-  steadyClock->advance(1_day);
+  m_steadyClock->advance(1_day);
   BOOST_CHECK_EQUAL(time::system_clock::now().time_since_epoch(),
                     time::UnitTestClockTraits<time::system_clock>::getDefaultStartTime());
 
-  systemClock->advance(1_day);
+  m_systemClock->advance(1_day);
   BOOST_CHECK_GT(time::system_clock::now().time_since_epoch(),
                  time::UnitTestClockTraits<time::system_clock>::getDefaultStartTime());
 
@@ -55,7 +55,7 @@
     time::fromUnixTimestamp(time::milliseconds(1390966967032LL));
   BOOST_CHECK_GT(time::system_clock::now(), referenceTime);
 
-  systemClock->setNow(referenceTime.time_since_epoch());
+  m_systemClock->setNow(referenceTime.time_since_epoch());
   BOOST_CHECK_EQUAL(time::system_clock::now(), referenceTime);
 
   BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(time::system_clock::now()),
@@ -98,36 +98,36 @@
   BOOST_CHECK_EQUAL(time::steady_clock::now().time_since_epoch(),
                     time::steady_clock::duration::zero());
 
-  systemClock->advance(36500_days);
+  m_systemClock->advance(36500_days);
   BOOST_CHECK_EQUAL(time::steady_clock::now().time_since_epoch(),
                     time::steady_clock::duration::zero());
 
-  steadyClock->advance(100_ns);
+  m_steadyClock->advance(100_ns);
   BOOST_CHECK_EQUAL(time::steady_clock::now().time_since_epoch(), 100_ns);
 
-  steadyClock->advance(100_us);
+  m_steadyClock->advance(100_us);
   BOOST_CHECK_EQUAL(time::steady_clock::now().time_since_epoch(), 100100_ns);
 
-  steadyClock->setNow(1_ms);
+  m_steadyClock->setNow(1_ms);
   BOOST_CHECK_EQUAL(time::steady_clock::now().time_since_epoch(), 1000000_ns);
 
   BOOST_CHECK_EQUAL(boost::lexical_cast<std::string>(time::steady_clock::now()),
                     "1000000 nanoseconds since unit test beginning");
 }
 
-BOOST_AUTO_TEST_CASE(Scheduler)
+BOOST_FIXTURE_TEST_CASE(Scheduler, IoFixture)
 {
-  ndn::Scheduler scheduler(io);
+  ndn::Scheduler scheduler(m_io);
 
   bool hasFired = false;
   scheduler.schedule(100_s, [&] { hasFired = true; });
 
-  io.poll();
+  m_io.poll();
   BOOST_CHECK_EQUAL(hasFired, false);
 
-  steadyClock->advance(100_s);
+  m_steadyClock->advance(100_s);
 
-  io.poll();
+  m_io.poll();
   BOOST_CHECK_EQUAL(hasFired, true);
 }