diff --git a/libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait_for.pass.cpp b/libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait_for.pass.cpp
--- a/libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait_for.pass.cpp
+++ b/libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait_for.pass.cpp
@@ -44,8 +44,9 @@
     test1 = 1;
     cv.notify_one();
     Clock::time_point t0 = Clock::now();
+    Clock::time_point wait_end = t0 + milliseconds(250);
     while (test2 == 0 &&
-           cv.wait_for(lk, milliseconds(250)) == std::cv_status::no_timeout)
+           cv.wait_for(lk, wait_end - Clock::now()) == std::cv_status::no_timeout)
         ;
     Clock::time_point t1 = Clock::now();
     if (runs == 0)
diff --git a/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_for.pass.cpp b/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_for.pass.cpp
--- a/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_for.pass.cpp
+++ b/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_for.pass.cpp
@@ -47,8 +47,9 @@
     test1 = 1;
     cv.notify_one();
     Clock::time_point t0 = Clock::now();
+    Clock::time_point wait_end = t0 + milliseconds(250);
     while (test2 == 0 &&
-           cv.wait_for(lk, milliseconds(250)) == std::cv_status::no_timeout)
+           cv.wait_for(lk, wait_end - Clock::now()) == std::cv_status::no_timeout)
         ;
     Clock::time_point t1 = Clock::now();
     if (runs == 0)