diff --git a/core/global-io.cpp b/core/global-io.cpp
index 48566f6..7eb6a56 100644
--- a/core/global-io.cpp
+++ b/core/global-io.cpp
@@ -24,33 +24,31 @@
  */
 
 #include "global-io.hpp"
-#include <boost/thread/tss.hpp>
+#include "scheduler.hpp"
 
 namespace nfd {
 
-namespace scheduler {
-// defined in scheduler.cpp
+namespace detail {
+
 void
-resetGlobalScheduler();
-} // namespace scheduler
-
-
-static boost::thread_specific_ptr<boost::asio::io_service> g_ioService;
-
-boost::asio::io_service&
-getGlobalIoService()
+SimulatorIo::post(const std::function<void()>& callback)
 {
-  if (g_ioService.get() == nullptr) {
-    g_ioService.reset(new boost::asio::io_service());
-  }
-  return *g_ioService;
+  scheduler::schedule(time::seconds(0), callback);
 }
 
 void
-resetGlobalIoService()
+SimulatorIodispatch(const std::function<void()>& callback)
 {
-  scheduler::resetGlobalScheduler();
-  g_ioService.reset();
+  scheduler::schedule(time::seconds(0), callback);
+}
+
+} // namespace detail
+
+detail::SimulatorIo&
+getGlobalIoService()
+{
+  static detail::SimulatorIo io;
+  return io;
 }
 
 } // namespace nfd
diff --git a/core/global-io.hpp b/core/global-io.hpp
index d5030ab..6a76c57 100644
--- a/core/global-io.hpp
+++ b/core/global-io.hpp
@@ -29,19 +29,27 @@
 
 namespace nfd {
 
-/** \return the global io_service instance
- */
-boost::asio::io_service&
-getGlobalIoService();
+namespace detail {
 
-#ifdef WITH_TESTS
-/** \brief delete the global io_service instance
- *
- *  It will be recreated at the next invocation of getGlobalIoService.
+/**
+ * @brief Simulator-based IO that implements a few interfaces from boost::asio::io_service
  */
-void
-resetGlobalIoService();
-#endif
+class SimulatorIo
+{
+public:
+  void
+  post(const std::function<void()>& callback);
+
+  void
+  dispatch(const std::function<void()>& callback);
+};
+
+} // namespace detail
+
+/** \return Simulator-based IO object
+ */
+detail::SimulatorIo&
+getGlobalIoService();
 
 } // namespace nfd
 
diff --git a/core/scheduler.cpp b/core/scheduler.cpp
index 177045f..725f81a 100644
--- a/core/scheduler.cpp
+++ b/core/scheduler.cpp
@@ -37,7 +37,7 @@
 getGlobalScheduler()
 {
   if (g_scheduler.get() == nullptr) {
-    g_scheduler.reset(new Scheduler(getGlobalIoService()));
+    g_scheduler.reset(new Scheduler(*static_cast<boost::asio::io_service*>(nullptr)));
   }
 
   return *g_scheduler;
diff --git a/core/scheduler.hpp b/core/scheduler.hpp
index b846c64..6e87199 100644
--- a/core/scheduler.hpp
+++ b/core/scheduler.hpp
@@ -49,6 +49,9 @@
 void
 cancel(const EventId& eventId);
 
+Scheduler&
+getGlobalScheduler();
+
 /** \brief cancels an event automatically upon destruction
  */
 class ScopedEventId : noncopyable