Index: test/libcxx/thread/thread.mutex/thread_safety_annotations_not_enabled.pass.cpp
===================================================================
--- test/libcxx/thread/thread.mutex/thread_safety_annotations_not_enabled.pass.cpp
+++ test/libcxx/thread/thread.mutex/thread_safety_annotations_not_enabled.pass.cpp
@@ -7,6 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+// UNSUPPORTED: libcpp-has-no-threads
+
 // <mutex>
 
 // This test does not define _LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS so it
Index: test/libcxx/thread/thread.mutex/thread_safety_lock_guard.pass.cpp
===================================================================
--- test/libcxx/thread/thread.mutex/thread_safety_lock_guard.pass.cpp
+++ test/libcxx/thread/thread.mutex/thread_safety_lock_guard.pass.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+// UNSUPPORTED: libcpp-has-no-threads
 // REQUIRES: thread-safety
 
 // <mutex>
Index: test/libcxx/thread/thread.mutex/thread_safety_lock_unlock.pass.cpp
===================================================================
--- test/libcxx/thread/thread.mutex/thread_safety_lock_unlock.pass.cpp
+++ test/libcxx/thread/thread.mutex/thread_safety_lock_unlock.pass.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+// UNSUPPORTED: libcpp-has-no-threads
 // REQUIRES: thread-safety
 
 // <mutex>
Index: test/libcxx/thread/thread.mutex/thread_safety_missing_unlock.fail.cpp
===================================================================
--- test/libcxx/thread/thread.mutex/thread_safety_missing_unlock.fail.cpp
+++ test/libcxx/thread/thread.mutex/thread_safety_missing_unlock.fail.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+// UNSUPPORTED: libcpp-has-no-threads
 // REQUIRES: thread-safety
 
 // <mutex>
Index: test/libcxx/thread/thread.mutex/thread_safety_requires_capability.pass.cpp
===================================================================
--- test/libcxx/thread/thread.mutex/thread_safety_requires_capability.pass.cpp
+++ test/libcxx/thread/thread.mutex/thread_safety_requires_capability.pass.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+// UNSUPPORTED: libcpp-has-no-threads
 // REQUIRES: thread-safety
 
 // <mutex>
Index: test/std/thread/futures/futures.promise/copy_assign.fail.cpp
===================================================================
--- test/std/thread/futures/futures.promise/copy_assign.fail.cpp
+++ test/std/thread/futures/futures.promise/copy_assign.fail.cpp
@@ -6,6 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
 
 // <future>
 
Index: test/std/thread/futures/futures.promise/copy_ctor.fail.cpp
===================================================================
--- test/std/thread/futures/futures.promise/copy_ctor.fail.cpp
+++ test/std/thread/futures/futures.promise/copy_ctor.fail.cpp
@@ -6,6 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
 
 // <future>
 
Index: test/std/thread/futures/futures.tas/futures.task.members/assign_copy.fail.cpp
===================================================================
--- test/std/thread/futures/futures.tas/futures.task.members/assign_copy.fail.cpp
+++ test/std/thread/futures/futures.tas/futures.task.members/assign_copy.fail.cpp
@@ -6,7 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-
+//
+// UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03
 
 // <future>
Index: test/std/thread/futures/futures.tas/futures.task.members/ctor1.fail.cpp
===================================================================
--- test/std/thread/futures/futures.tas/futures.task.members/ctor1.fail.cpp
+++ test/std/thread/futures/futures.tas/futures.task.members/ctor1.fail.cpp
@@ -6,7 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-
+//
+// UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03
 
 // <future>
Index: test/std/thread/futures/futures.tas/futures.task.members/ctor2.fail.cpp
===================================================================
--- test/std/thread/futures/futures.tas/futures.task.members/ctor2.fail.cpp
+++ test/std/thread/futures/futures.tas/futures.task.members/ctor2.fail.cpp
@@ -6,7 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-
+//
+// UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03
 
 // <future>
Index: test/std/thread/futures/futures.tas/futures.task.members/ctor_copy.fail.cpp
===================================================================
--- test/std/thread/futures/futures.tas/futures.task.members/ctor_copy.fail.cpp
+++ test/std/thread/futures/futures.tas/futures.task.members/ctor_copy.fail.cpp
@@ -6,7 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-
+//
+// UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03
 
 // <future>
Index: test/std/thread/futures/futures.unique_future/copy_assign.fail.cpp
===================================================================
--- test/std/thread/futures/futures.unique_future/copy_assign.fail.cpp
+++ test/std/thread/futures/futures.unique_future/copy_assign.fail.cpp
@@ -6,6 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
 
 // <future>
 
Index: test/std/thread/futures/futures.unique_future/copy_ctor.fail.cpp
===================================================================
--- test/std/thread/futures/futures.unique_future/copy_ctor.fail.cpp
+++ test/std/thread/futures/futures.unique_future/copy_ctor.fail.cpp
@@ -6,6 +6,8 @@
 // Source Licenses. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
 
 // <future>
 
Index: test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/assign.fail.cpp
===================================================================
--- test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/assign.fail.cpp
+++ test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/assign.fail.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
+// UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 
 // <shared_mutex>
Index: test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/copy.fail.cpp
===================================================================
--- test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/copy.fail.cpp
+++ test/std/thread/thread.mutex/thread.mutex.requirements/thread.shared_mutex.requirements/thread.shared_mutex.class/copy.fail.cpp
@@ -7,6 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
+// UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 
 // <shared_mutex>