diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/default.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/default.pass.cpp
index b278419df6eed..7a8d096994fff 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/default.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/default.pass.cpp
@@ -19,9 +19,9 @@
 
 #include "test_macros.h"
 
-int main(int, char**)
-{
-    std::shared_timed_mutex m;
+int main(int, char**) {
+  std::shared_timed_mutex m;
+  (void)m;
 
   return 0;
 }
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.class/default.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.class/default.pass.cpp
index d13a0ad435aea..c7f207372ac42 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.class/default.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.class/default.pass.cpp
@@ -18,9 +18,9 @@
 
 #include "test_macros.h"
 
-int main(int, char**)
-{
-    std::timed_mutex m;
+int main(int, char**) {
+  std::timed_mutex m;
+  (void)m;
 
   return 0;
 }
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.recursive/default.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.recursive/default.pass.cpp
index 73e2e7a3a5ab9..3096e031855a2 100644
--- a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.recursive/default.pass.cpp
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.timedmutex.requirements/thread.timedmutex.recursive/default.pass.cpp
@@ -18,9 +18,9 @@
 
 #include "test_macros.h"
 
-int main(int, char**)
-{
-    std::recursive_timed_mutex m;
+int main(int, char**) {
+  std::recursive_timed_mutex m;
+  (void)m;
 
   return 0;
 }