diff --git a/libc/thread/thread.h b/libc/thread/thread.h
index 1c804d7a9..b7ac8a119 100644
--- a/libc/thread/thread.h
+++ b/libc/thread/thread.h
@@ -205,11 +205,9 @@ int pthread_mutex_unlock(pthread_mutex_t *) dontthrow paramsnonnull();
 int pthread_mutex_wipe_np(pthread_mutex_t *) libcesque paramsnonnull();
 int pthread_mutexattr_destroy(pthread_mutexattr_t *) libcesque paramsnonnull();
 int pthread_mutexattr_getpshared(const pthread_mutexattr_t *, int *) libcesque paramsnonnull();
-int pthread_mutexattr_getrobust(const pthread_mutexattr_t *, int *) libcesque paramsnonnull();
 int pthread_mutexattr_gettype(const pthread_mutexattr_t *, int *) libcesque paramsnonnull();
 int pthread_mutexattr_init(pthread_mutexattr_t *) libcesque paramsnonnull();
 int pthread_mutexattr_setpshared(pthread_mutexattr_t *, int) libcesque paramsnonnull();
-int pthread_mutexattr_setrobust(const pthread_mutexattr_t *, int) libcesque paramsnonnull();
 int pthread_mutexattr_settype(pthread_mutexattr_t *, int) libcesque paramsnonnull();
 int pthread_once(pthread_once_t *, void (*)(void)) paramsnonnull();
 int pthread_orphan_np(void) libcesque;