diff --git a/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock.pass.cpp
index 4882606..6ce1d92 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock.pass.cpp
@@ -8,6 +8,8 @@
 //
 // UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03, c++11
+//
+// FLAKY_TEST.
 
 // <shared_mutex>
 
diff --git a/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.locking/try_lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.locking/try_lock.pass.cpp
index a6247df..3ddfd75 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.locking/try_lock.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.locking/try_lock.pass.cpp
@@ -7,6 +7,8 @@
 //===----------------------------------------------------------------------===//
 //
 // UNSUPPORTED: libcpp-has-no-threads
+//
+// FLAKY_TEST.
 
 // <mutex>
 
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.mutex.requirements.mutex/thread.mutex.class/try_lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.mutex.requirements.mutex/thread.mutex.class/try_lock.pass.cpp
index c5abe77..3a6b8a3 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.mutex.requirements.mutex/thread.mutex.class/try_lock.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.mutex.requirements.mutex/thread.mutex.class/try_lock.pass.cpp
@@ -7,6 +7,8 @@
 //===----------------------------------------------------------------------===//
 //
 // UNSUPPORTED: libcpp-has-no-threads
+//
+// FLAKY_TEST.
 
 // <mutex>
 
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.mutex.requirements.mutex/thread.mutex.recursive/try_lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.mutex.requirements.mutex/thread.mutex.recursive/try_lock.pass.cpp
index 8a133c1..fd8b652 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.mutex.requirements.mutex/thread.mutex.recursive/try_lock.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.mutex.requirements.mutex/thread.mutex.recursive/try_lock.pass.cpp
@@ -8,6 +8,8 @@
 //
 // UNSUPPORTED: libcpp-has-no-threads
 
+// FLAKY_TEST.
+
 // <mutex>
 
 // class recursive_mutex;
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock.pass.cpp
index 9932bd4..820c4a5 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock.pass.cpp
@@ -8,6 +8,8 @@
 //
 // UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03, c++11
+//
+// FLAKY_TEST.
 
 // <shared_mutex>
 
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.class/try_lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.class/try_lock.pass.cpp
index 769b22e..058cdd9 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.class/try_lock.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.class/try_lock.pass.cpp
@@ -7,6 +7,8 @@
 //===----------------------------------------------------------------------===//
 //
 // UNSUPPORTED: libcpp-has-no-threads
+//
+// FLAKY_TEST.
 
 // <mutex>
 
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.recursive/try_lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.recursive/try_lock.pass.cpp
index d5517b1..0b0f2a3 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.recursive/try_lock.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.recursive/try_lock.pass.cpp
@@ -7,6 +7,8 @@
 //===----------------------------------------------------------------------===//
 //
 // UNSUPPORTED: libcpp-has-no-threads
+//
+// FLAKY_TEST.
 
 // <mutex>