diff --git a/tests/core/limited-io.cpp b/tests/core/limited-io.cpp
index b381696..1eba63d 100644
--- a/tests/core/limited-io.cpp
+++ b/tests/core/limited-io.cpp
@@ -13,7 +13,7 @@
 NFD_LOG_INIT("LimitedIo");
 
 const int LimitedIo::UNLIMITED_OPS = std::numeric_limits<int>::max();
-const time::Duration LimitedIo::UNLIMITED_TIME = time::nanoseconds(-1);
+const time::nanoseconds LimitedIo::UNLIMITED_TIME = time::nanoseconds::min();
 
 LimitedIo::LimitedIo()
   : m_isRunning(false)
@@ -22,14 +22,14 @@
 }
 
 LimitedIo::StopReason
-LimitedIo::run(int nOpsLimit, time::Duration nTimeLimit)
+LimitedIo::run(int nOpsLimit, const time::nanoseconds& nTimeLimit)
 {
   BOOST_ASSERT(!m_isRunning);
   m_isRunning = true;
   
   m_reason = NO_WORK;
   m_nOpsRemaining = nOpsLimit;
-  if (nTimeLimit != UNLIMITED_TIME) {
+  if (nTimeLimit >= time::nanoseconds::zero()) {
     m_timeout = scheduler::schedule(nTimeLimit, bind(&LimitedIo::afterTimeout, this));
   }
   
diff --git a/tests/core/limited-io.hpp b/tests/core/limited-io.hpp
index 0aae290..d3968c2 100644
--- a/tests/core/limited-io.hpp
+++ b/tests/core/limited-io.hpp
@@ -38,7 +38,7 @@
    *  \param nTimeLimit time limit, pass UNLIMITED_TIME for no limit
    */
   StopReason
-  run(int nOpsLimit, time::Duration nTimeLimit);
+  run(int nOpsLimit, const time::nanoseconds& nTimeLimit);
   
   /// count an operation
   void
@@ -53,7 +53,7 @@
 
 public:
   static const int UNLIMITED_OPS;
-  static const time::Duration UNLIMITED_TIME;
+  static const time::nanoseconds UNLIMITED_TIME;
 
 private:
   bool m_isRunning;
diff --git a/tests/core/scheduler.cpp b/tests/core/scheduler.cpp
index 806c982..87c75cf 100644
--- a/tests/core/scheduler.cpp
+++ b/tests/core/scheduler.cpp
@@ -57,18 +57,20 @@
 
 BOOST_FIXTURE_TEST_CASE(Events, SchedulerFixture)
 {
-  scheduler::schedule(time::seconds(0.5), bind(&SchedulerFixture::event1, this));
+  scheduler::schedule(time::milliseconds(500), bind(&SchedulerFixture::event1, this));
 
-  EventId i = scheduler::schedule(time::seconds(1.0), bind(&SchedulerFixture::event2, this));
+  EventId i = scheduler::schedule(time::seconds(1), bind(&SchedulerFixture::event2, this));
   scheduler::cancel(i);
 
-  scheduler::schedule(time::seconds(0.25), bind(&SchedulerFixture::event3, this));
+  scheduler::schedule(time::milliseconds(250), bind(&SchedulerFixture::event3, this));
 
-  i = scheduler::schedule(time::seconds(0.05), bind(&SchedulerFixture::event2, this));
+  i = scheduler::schedule(time::milliseconds(50), bind(&SchedulerFixture::event2, this));
   scheduler::cancel(i);
 
   // TODO deprecate periodic event
-  i = scheduler::getGlobalScheduler().schedulePeriodicEvent(time::seconds(0.3), time::seconds(0.1), bind(&SchedulerFixture::event4, this));
+  i = scheduler::getGlobalScheduler().schedulePeriodicEvent(time::milliseconds(300),
+                                                            time::milliseconds(100),
+                                                            bind(&SchedulerFixture::event4, this));
   scheduler::schedule(time::seconds(1), bind(&scheduler::cancel, i));
 
   g_io.run();
@@ -98,7 +100,7 @@
 
 BOOST_FIXTURE_TEST_CASE(SelfCancel, SelfCancelFixture)
 {
-  m_selfEventId = scheduler::schedule(time::seconds(0.1),
+  m_selfEventId = scheduler::schedule(time::milliseconds(100),
                                       bind(&SelfCancelFixture::cancelSelf, this));
 
   BOOST_REQUIRE_NO_THROW(g_io.run());