diff --git a/winsup/cygwin/include/pthread.h b/winsup/cygwin/include/pthread.h
index 3dfc2bc80..fed616532 100644
--- a/winsup/cygwin/include/pthread.h
+++ b/winsup/cygwin/include/pthread.h
@@ -187,7 +187,7 @@ int pthread_spin_unlock (pthread_spinlock_t *);
 #endif
 
 /* RW Locks */
-#if __XSI_VISIBLE >= 500 || __POSIX_VISIBLE >= 200112
+#if __XSI_VISIBLE >= 500 || __POSIX_VISIBLE >= 200112 || __cplusplus >= 201402L
 int pthread_rwlock_destroy (pthread_rwlock_t *rwlock);
 int pthread_rwlock_init (pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr);
 int pthread_rwlock_rdlock (pthread_rwlock_t *rwlock);