diff --git a/tests/daemon/fw/algorithm.t.cpp b/tests/daemon/fw/algorithm.t.cpp
index 4a86d78..d0bd2f0 100644
--- a/tests/daemon/fw/algorithm.t.cpp
+++ b/tests/daemon/fw/algorithm.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,
@@ -155,7 +155,7 @@
   auto face2 = make_shared<DummyFace>();
   auto face3 = make_shared<DummyFace>();
 
-  auto interest = makeInterest("/totzXG0d", false, nullopt, 29321);
+  auto interest = makeInterest("/totzXG0d", false, std::nullopt, 29321);
   pit::Entry entry(*interest);
   BOOST_CHECK_EQUAL(hasPendingOutRecords(entry), false);
 
diff --git a/tests/daemon/fw/choose-strategy.hpp b/tests/daemon/fw/choose-strategy.hpp
index 0da7b84..cfb5ee6 100644
--- a/tests/daemon/fw/choose-strategy.hpp
+++ b/tests/daemon/fw/choose-strategy.hpp
@@ -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,
@@ -48,7 +48,7 @@
  *  \return a reference to the strategy
  */
 template<typename S>
-typename std::enable_if<std::is_base_of<fw::Strategy, S>::value, S&>::type
+std::enable_if_t<std::is_base_of_v<fw::Strategy, S>, S&>
 choose(Forwarder& forwarder, const Name& prefix = "/",
        const Name& instanceName = S::getStrategyName())
 {
diff --git a/tests/daemon/fw/forwarder.t.cpp b/tests/daemon/fw/forwarder.t.cpp
index 5fb2776..eef2cea 100644
--- a/tests/daemon/fw/forwarder.t.cpp
+++ b/tests/daemon/fw/forwarder.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,
@@ -160,17 +160,17 @@
   auto face2 = addFace();
 
   Pit& pit = forwarder.getPit();
-  auto interestA1 = makeInterest("/A", false, nullopt, 8378);
+  auto interestA1 = makeInterest("/A", false, std::nullopt, 8378);
   auto pitA = pit.insert(*interestA1).first;
   pitA->insertOrUpdateInRecord(*face1, *interestA1);
 
-  auto interestA2 = makeInterest("/A", false, nullopt, 1698);
+  auto interestA2 = makeInterest("/A", false, std::nullopt, 1698);
   auto outA2 = forwarder.onOutgoingInterest(*interestA2, *face2, pitA);
   BOOST_REQUIRE(outA2 != nullptr);
   BOOST_CHECK_EQUAL(outA2->getLastNonce(), 1698);
 
   // This packet will be dropped because HopLimit=0
-  auto interestA3 = makeInterest("/A", false, nullopt, 9876);
+  auto interestA3 = makeInterest("/A", false, std::nullopt, 9876);
   interestA3->setHopLimit(0);
   auto outA3 = forwarder.onOutgoingInterest(*interestA3, *face2, pitA);
   BOOST_CHECK(outA3 == nullptr);
@@ -468,10 +468,10 @@
   Pit& pit = forwarder.getPit();
 
   // dispatch to the correct strategy
-  auto interest1 = makeInterest("/A/AYJqayrzF", false, nullopt, 562);
+  auto interest1 = makeInterest("/A/AYJqayrzF", false, std::nullopt, 562);
   auto pit1 = pit.insert(*interest1).first;
   pit1->insertOrUpdateOutRecord(*face1, *interest1);
-  auto interest2 = makeInterest("/B/EVyP73ru", false, nullopt, 221);
+  auto interest2 = makeInterest("/B/EVyP73ru", false, std::nullopt, 221);
   auto pit2 = pit.insert(*interest2).first;
   pit2->insertOrUpdateOutRecord(*face1, *interest2);
 
@@ -496,7 +496,7 @@
   BOOST_CHECK_EQUAL(outRecord1->getIncomingNack()->getReason(), lp::NackReason::CONGESTION);
 
   // drop if no PIT entry
-  auto nack3 = makeNack(*makeInterest("/yEcw5HhdM", false, nullopt, 243), lp::NackReason::CONGESTION);
+  auto nack3 = makeNack(*makeInterest("/yEcw5HhdM", false, std::nullopt, 243), lp::NackReason::CONGESTION);
   strategyA.afterReceiveNack_count = 0;
   strategyB.afterReceiveNack_count = 0;
   forwarder.onIncomingNack(nack3, FaceEndpoint(*face1, 0));
@@ -504,7 +504,7 @@
   BOOST_CHECK_EQUAL(strategyB.afterReceiveNack_count, 0);
 
   // drop if no out-record
-  auto interest4 = makeInterest("/Etab4KpY", false, nullopt, 157);
+  auto interest4 = makeInterest("/Etab4KpY", false, std::nullopt, 157);
   auto pit4 = pit.insert(*interest4).first;
   pit4->insertOrUpdateOutRecord(*face1, *interest4);
 
@@ -516,7 +516,7 @@
   BOOST_CHECK_EQUAL(strategyB.afterReceiveNack_count, 0);
 
   // drop if Nonce does not match out-record
-  auto nack4b = makeNack(*makeInterest("/Etab4KpY", false, nullopt, 294), lp::NackReason::CONGESTION);
+  auto nack4b = makeNack(*makeInterest("/Etab4KpY", false, std::nullopt, 294), lp::NackReason::CONGESTION);
   strategyA.afterReceiveNack_count = 0;
   strategyB.afterReceiveNack_count = 0;
   forwarder.onIncomingNack(nack4b, FaceEndpoint(*face1, 0));
@@ -549,7 +549,7 @@
   nackHeader.setReason(lp::NackReason::CONGESTION);
 
   // don't send Nack if there's no in-record
-  auto interest1 = makeInterest("/fM5IVEtC", false, nullopt, 719);
+  auto interest1 = makeInterest("/fM5IVEtC", false, std::nullopt, 719);
   auto pit1 = pit.insert(*interest1).first;
   pit1->insertOrUpdateInRecord(*face1, *interest1);
 
@@ -558,10 +558,10 @@
   BOOST_CHECK_EQUAL(face2->sentNacks.size(), 0);
 
   // send Nack with correct Nonce
-  auto interest2a = makeInterest("/Vi8tRm9MG3", false, nullopt, 152);
+  auto interest2a = makeInterest("/Vi8tRm9MG3", false, std::nullopt, 152);
   auto pit2 = pit.insert(*interest2a).first;
   pit2->insertOrUpdateInRecord(*face1, *interest2a);
-  auto interest2b = makeInterest("/Vi8tRm9MG3", false, nullopt, 808);
+  auto interest2b = makeInterest("/Vi8tRm9MG3", false, std::nullopt, 808);
   pit2->insertOrUpdateInRecord(*face2, *interest2b);
   face1->sentNacks.clear();
   face2->sentNacks.clear();
@@ -588,7 +588,7 @@
   BOOST_CHECK(inRecord2b == pit2->in_end());
 
   // don't send Nack to multi-access face
-  auto interest2c = makeInterest("/Vi8tRm9MG3", false, nullopt, 228);
+  auto interest2c = makeInterest("/Vi8tRm9MG3", false, std::nullopt, 228);
   pit2->insertOrUpdateInRecord(*face3, *interest2c);
 
   face3->sentNacks.clear();
@@ -596,7 +596,7 @@
   BOOST_CHECK_EQUAL(face3->sentNacks.size(), 0);
 
   // don't send Nack to face with invalid ID
-  auto interest1b = makeInterest("/fM5IVEtC", false, nullopt, 553);
+  auto interest1b = makeInterest("/fM5IVEtC", false, std::nullopt, 553);
   pit1->insertOrUpdateInRecord(*face4, *interest1b);
 
   face4->sentNacks.clear();
@@ -620,19 +620,19 @@
 
   // receive Interest on face1
   face1->sentNacks.clear();
-  auto interest1a = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, nullopt, 732);
+  auto interest1a = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, std::nullopt, 732);
   face1->receiveInterest(*interest1a, 0);
   BOOST_CHECK(face1->sentNacks.empty());
 
   // receive Interest with duplicate Nonce on face1: legit retransmission
   face1->sentNacks.clear();
-  auto interest1b = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, nullopt, 732);
+  auto interest1b = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, std::nullopt, 732);
   face1->receiveInterest(*interest1b, 0);
   BOOST_CHECK(face1->sentNacks.empty());
 
   // receive Interest with duplicate Nonce on face2
   face2->sentNacks.clear();
-  auto interest2a = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, nullopt, 732);
+  auto interest2a = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, std::nullopt, 732);
   face2->receiveInterest(*interest2a, 0);
   BOOST_REQUIRE_EQUAL(face2->sentNacks.size(), 1);
   BOOST_CHECK_EQUAL(face2->sentNacks.back().getInterest().wireEncode(), interest2a->wireEncode());
@@ -640,13 +640,13 @@
 
   // receive Interest with new Nonce on face2
   face2->sentNacks.clear();
-  auto interest2b = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, nullopt, 944);
+  auto interest2b = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, std::nullopt, 944);
   face2->receiveInterest(*interest2b, 0);
   BOOST_CHECK(face2->sentNacks.empty());
 
   // receive Interest with duplicate Nonce on face3, don't send Nack to multi-access face
   face3->sentNacks.clear();
-  auto interest3a = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, nullopt, 732);
+  auto interest3a = makeInterest("/zT4XwK0Hnx/28JBUvbEzc", false, std::nullopt, 732);
   face3->receiveInterest(*interest3a, 0);
   BOOST_CHECK(face3->sentNacks.empty());
 }
diff --git a/tests/daemon/fw/strategy-nack-return.t.cpp b/tests/daemon/fw/strategy-nack-return.t.cpp
index 73db46c..a091fb5 100644
--- a/tests/daemon/fw/strategy-nack-return.t.cpp
+++ b/tests/daemon/fw/strategy-nack-return.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,
@@ -97,8 +97,8 @@
   this->fib.addOrUpdateNextHop(fibEntry, *this->face4, 20);
   this->fib.addOrUpdateNextHop(fibEntry, *this->face5, 30);
 
-  auto interest1 = makeInterest("/McQYjMbm", false, nullopt, 992);
-  auto interest2 = makeInterest("/McQYjMbm", false, nullopt, 114);
+  auto interest1 = makeInterest("/McQYjMbm", false, std::nullopt, 992);
+  auto interest2 = makeInterest("/McQYjMbm", false, std::nullopt, 114);
   shared_ptr<pit::Entry> pitEntry = this->pit.insert(*interest1).first;
   pitEntry->insertOrUpdateInRecord(*this->face1, *interest1);
   pitEntry->insertOrUpdateInRecord(*this->face2, *interest2);
@@ -136,7 +136,7 @@
   this->fib.addOrUpdateNextHop(fibEntry, *this->face4, 20);
   this->fib.addOrUpdateNextHop(fibEntry, *this->face5, 30);
 
-  auto interest1 = makeInterest("/aS9FAyUV19", false, nullopt, 286);
+  auto interest1 = makeInterest("/aS9FAyUV19", false, std::nullopt, 286);
   shared_ptr<pit::Entry> pitEntry = this->pit.insert(*interest1).first;
   pitEntry->insertOrUpdateInRecord(*this->face1, *interest1);
   pitEntry->insertOrUpdateOutRecord(*this->face3, *interest1);
@@ -178,7 +178,7 @@
   pitEntry->insertOrUpdateOutRecord(*this->face3, *interest1);
 
   this->advanceClocks(300_ms);
-  auto interest2 = makeInterest("/sIYw0TXWDj", false, nullopt, 223);
+  auto interest2 = makeInterest("/sIYw0TXWDj", false, std::nullopt, 223);
   pitEntry->insertOrUpdateInRecord(*this->face1, *interest2);
   pitEntry->insertOrUpdateOutRecord(*this->face4, *interest2);
 
@@ -325,7 +325,7 @@
   fib.addOrUpdateNextHop(fibEntry, *face4, 20);
   fib.addOrUpdateNextHop(fibEntry, *face5, 30);
 
-  auto interest1 = makeInterest("/F6sEwB24I", false, nullopt, 282);
+  auto interest1 = makeInterest("/F6sEwB24I", false, std::nullopt, 282);
   shared_ptr<pit::Entry> pitEntry = pit.insert(*interest1).first;
   pitEntry->insertOrUpdateInRecord(*face1, *interest1);
   pitEntry->insertOrUpdateOutRecord(*face3, *interest1);
diff --git a/tests/daemon/fw/strategy-scope-control.t.cpp b/tests/daemon/fw/strategy-scope-control.t.cpp
index 6fd052e..86e9540 100644
--- a/tests/daemon/fw/strategy-scope-control.t.cpp
+++ b/tests/daemon/fw/strategy-scope-control.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,
@@ -229,7 +229,7 @@
   this->fib.addOrUpdateNextHop(*fibEntry, *this->localFace4, 10);
   this->fib.addOrUpdateNextHop(*fibEntry, *this->nonLocalFace2, 20);
 
-  auto interest = makeInterest("/localhost/A/1", false, nullopt, 1460);
+  auto interest = makeInterest("/localhost/A/1", false, std::nullopt, 1460);
   shared_ptr<pit::Entry> pitEntry = this->pit.insert(*interest).first;
   pitEntry->insertOrUpdateInRecord(*this->localFace3, *interest);
   lp::Nack nack = makeNack(*interest, lp::NackReason::NO_ROUTE);
@@ -254,7 +254,7 @@
   this->fib.addOrUpdateNextHop(*fibEntry, *this->localFace4, 10);
   this->fib.addOrUpdateNextHop(*fibEntry, *this->nonLocalFace2, 20);
 
-  auto interest = makeInterest("/localhop/A/1", false, nullopt, 1377);
+  auto interest = makeInterest("/localhop/A/1", false, std::nullopt, 1377);
   shared_ptr<pit::Entry> pitEntry = this->pit.insert(*interest).first;
   pitEntry->insertOrUpdateInRecord(*this->nonLocalFace1, *interest);
   lp::Nack nack = makeNack(*interest, lp::NackReason::NO_ROUTE);