diff --git a/tests/thread_context_switch.cc b/tests/thread_context_switch.cc
index c3b19751b8..f462aa22d5 100644
--- a/tests/thread_context_switch.cc
+++ b/tests/thread_context_switch.cc
@@ -20,6 +20,7 @@
  * Copyright (C) 2015 Cloudius Systems, Ltd.
  */
 
+#include <experimental/optional>
 #include "core/thread.hh"
 #include "core/semaphore.hh"
 #include "core/app-template.hh"