diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index d481a1d..120bbc7 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -653,3 +653,26 @@
   GTEST_LOG_(INFO) << "This test does nothing.\n";
 #endif // __BIONIC__
 }
+
+TEST(pthread, pthread_mutex_timedlock) {
+  pthread_mutex_t m;
+  ASSERT_EQ(0, pthread_mutex_init(&m, NULL));
+
+  // If the mutex is already locked, pthread_mutex_timedlock should time out.
+  ASSERT_EQ(0, pthread_mutex_lock(&m));
+
+  timespec ts;
+  ASSERT_EQ(0, clock_gettime(CLOCK_REALTIME, &ts));
+  ts.tv_nsec += 1;
+  ASSERT_EQ(ETIMEDOUT, pthread_mutex_timedlock(&m, &ts));
+
+  // If the mutex is unlocked, pthread_mutex_timedlock should succeed.
+  ASSERT_EQ(0, pthread_mutex_unlock(&m));
+
+  ASSERT_EQ(0, clock_gettime(CLOCK_REALTIME, &ts));
+  ts.tv_nsec += 1;
+  ASSERT_EQ(0, pthread_mutex_timedlock(&m, &ts));
+
+  ASSERT_EQ(0, pthread_mutex_unlock(&m));
+  ASSERT_EQ(0, pthread_mutex_destroy(&m));
+}