diff --git a/winsup/cygwin/common.din b/winsup/cygwin/common.din
index f7c27fd4d..b09d3551f 100644
--- a/winsup/cygwin/common.din
+++ b/winsup/cygwin/common.din
@@ -1141,6 +1141,8 @@ pthread_mutexattr_setprotocol SIGFE
 pthread_mutexattr_setpshared SIGFE
 pthread_mutexattr_settype SIGFE
 pthread_once SIGFE
+pthread_rwlock_clockrdlock SIGFE
+pthread_rwlock_clockwrlock SIGFE
 pthread_rwlock_destroy SIGFE
 pthread_rwlock_init SIGFE
 pthread_rwlock_rdlock SIGFE
diff --git a/winsup/cygwin/include/pthread.h b/winsup/cygwin/include/pthread.h
index 6b7b6dde5..66d367d62 100644
--- a/winsup/cygwin/include/pthread.h
+++ b/winsup/cygwin/include/pthread.h
@@ -199,9 +199,17 @@ int pthread_spin_unlock (pthread_spinlock_t *);
 int pthread_rwlock_destroy (pthread_rwlock_t *);
 int pthread_rwlock_init (pthread_rwlock_t *, const pthread_rwlockattr_t *);
 int pthread_rwlock_rdlock (pthread_rwlock_t *);
+#if __GNU_VISIBLE
+int pthread_rwlock_clockrdlock (pthread_rwlock_t *, clockid_t,
+				const struct timespec *);
+#endif
 int pthread_rwlock_timedrdlock (pthread_rwlock_t *, const struct timespec *);
 int pthread_rwlock_tryrdlock (pthread_rwlock_t *);
 int pthread_rwlock_wrlock (pthread_rwlock_t *);
+#if __GNU_VISIBLE
+int pthread_rwlock_clockwrlock (pthread_rwlock_t *, clockid_t,
+				const struct timespec *);
+#endif
 int pthread_rwlock_timedwrlock (pthread_rwlock_t *, const struct timespec *);
 int pthread_rwlock_trywrlock (pthread_rwlock_t *);
 int pthread_rwlock_unlock (pthread_rwlock_t *);
diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 55184f8b9..4d0ea274f 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -3174,7 +3174,7 @@ pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
 }
 
 extern "C" int
-pthread_rwlock_timedrdlock (pthread_rwlock_t *rwlock,
+pthread_rwlock_clockrdlock (pthread_rwlock_t *rwlock, clockid_t clock_id,
 			    const struct timespec *abstime)
 {
   LARGE_INTEGER timeout;
@@ -3193,7 +3193,7 @@ pthread_rwlock_timedrdlock (pthread_rwlock_t *rwlock,
 
   __try
     {
-      int err = pthread_convert_abstime (CLOCK_REALTIME, abstime, &timeout);
+      int err = pthread_convert_abstime (clock_id, abstime, &timeout);
       if (err)
 	return err;
 
@@ -3204,6 +3204,13 @@ pthread_rwlock_timedrdlock (pthread_rwlock_t *rwlock,
   return EINVAL;
 }
 
+extern "C" int
+pthread_rwlock_timedrdlock (pthread_rwlock_t *rwlock,
+			    const struct timespec *abstime)
+{
+  return pthread_rwlock_clockrdlock (rwlock, CLOCK_REALTIME, abstime);
+}
+
 extern "C" int
 pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
 {
@@ -3229,7 +3236,7 @@ pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
 }
 
 extern "C" int
-pthread_rwlock_timedwrlock (pthread_rwlock_t *rwlock,
+pthread_rwlock_clockwrlock (pthread_rwlock_t *rwlock, clockid_t clock_id,
 			    const struct timespec *abstime)
 {
   LARGE_INTEGER timeout;
@@ -3248,7 +3255,7 @@ pthread_rwlock_timedwrlock (pthread_rwlock_t *rwlock,
 
   __try
     {
-      int err = pthread_convert_abstime (CLOCK_REALTIME, abstime, &timeout);
+      int err = pthread_convert_abstime (clock_id, abstime, &timeout);
       if (err)
 	return err;
 
@@ -3259,6 +3266,13 @@ pthread_rwlock_timedwrlock (pthread_rwlock_t *rwlock,
   return EINVAL;
 }
 
+extern "C" int
+pthread_rwlock_timedwrlock (pthread_rwlock_t *rwlock,
+			    const struct timespec *abstime)
+{
+  return pthread_rwlock_clockwrlock (rwlock, CLOCK_REALTIME, abstime);
+}
+
 extern "C" int
 pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
 {