diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index 2fa10bb..8b78a74 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -99,7 +99,11 @@
 int pthread_attr_destroy(pthread_attr_t* _Nonnull __attr);
 int pthread_attr_getdetachstate(const pthread_attr_t* _Nonnull __attr, int* _Nonnull __state);
 int pthread_attr_getguardsize(const pthread_attr_t* _Nonnull __attr, size_t* _Nonnull __size);
+
+#if __BIONIC_AVAILABILITY_GUARD(28)
 int pthread_attr_getinheritsched(const pthread_attr_t* _Nonnull __attr, int* _Nonnull __flag) __INTRODUCED_IN(28);
+#endif /* __BIONIC_AVAILABILITY_GUARD(28) */
+
 int pthread_attr_getschedparam(const pthread_attr_t* _Nonnull __attr, struct sched_param* _Nonnull __param);
 int pthread_attr_getschedpolicy(const pthread_attr_t* _Nonnull __attr, int* _Nonnull __policy);
 int pthread_attr_getscope(const pthread_attr_t* _Nonnull __attr, int* _Nonnull __scope);
@@ -108,7 +112,11 @@
 int pthread_attr_init(pthread_attr_t* _Nonnull __attr);
 int pthread_attr_setdetachstate(pthread_attr_t* _Nonnull __attr, int __state);
 int pthread_attr_setguardsize(pthread_attr_t* _Nonnull __attr, size_t __size);
+
+#if __BIONIC_AVAILABILITY_GUARD(28)
 int pthread_attr_setinheritsched(pthread_attr_t* _Nonnull __attr, int __flag) __INTRODUCED_IN(28);
+#endif /* __BIONIC_AVAILABILITY_GUARD(28) */
+
 int pthread_attr_setschedparam(pthread_attr_t* _Nonnull __attr, const struct sched_param* _Nonnull __param);
 int pthread_attr_setschedpolicy(pthread_attr_t* _Nonnull __attr, int __policy);
 int pthread_attr_setscope(pthread_attr_t* _Nonnull __attr, int __scope);
@@ -123,8 +131,12 @@
 int pthread_condattr_setpshared(pthread_condattr_t* _Nonnull __attr, int __shared);
 
 int pthread_cond_broadcast(pthread_cond_t* _Nonnull __cond);
+
+#if __BIONIC_AVAILABILITY_GUARD(30)
 int pthread_cond_clockwait(pthread_cond_t* _Nonnull __cond, pthread_mutex_t* _Nonnull __mutex, clockid_t __clock,
                            const struct timespec* _Nullable __timeout) __INTRODUCED_IN(30);
+#endif /* __BIONIC_AVAILABILITY_GUARD(30) */
+
 int pthread_cond_destroy(pthread_cond_t* _Nonnull __cond);
 int pthread_cond_init(pthread_cond_t* _Nonnull __cond, const pthread_condattr_t* _Nullable __attr);
 int pthread_cond_signal(pthread_cond_t* _Nonnull __cond);
@@ -139,8 +151,12 @@
  * Note that pthread_cond_clockwait() allows specifying an arbitrary clock and has superseded this
  * function.
  */
+
+#if (!defined(__LP64__)) || (defined(__LP64__) && __ANDROID_API__ >= 28)
 int pthread_cond_timedwait_monotonic_np(pthread_cond_t* _Nonnull __cond, pthread_mutex_t* _Nonnull __mutex,
                                         const struct timespec* _Nullable __timeout) __INTRODUCED_IN_64(28);
+#endif /* (!defined(__LP64__)) || (defined(__LP64__) && __ANDROID_API__ >= 28) */
+
 int pthread_cond_wait(pthread_cond_t* _Nonnull __cond, pthread_mutex_t* _Nonnull __mutex);
 
 int pthread_create(pthread_t* _Nonnull __pthread_ptr, pthread_attr_t const* _Nullable __attr, void* _Nullable (* _Nonnull __start_routine)(void* _Nullable), void* _Nullable);
@@ -188,14 +204,26 @@
 int pthread_mutexattr_destroy(pthread_mutexattr_t* _Nonnull __attr);
 int pthread_mutexattr_getpshared(const pthread_mutexattr_t* _Nonnull __attr, int* _Nonnull __shared);
 int pthread_mutexattr_gettype(const pthread_mutexattr_t* _Nonnull __attr, int* _Nonnull __type);
+
+#if __BIONIC_AVAILABILITY_GUARD(28)
 int pthread_mutexattr_getprotocol(const pthread_mutexattr_t* _Nonnull __attr, int* _Nonnull __protocol) __INTRODUCED_IN(28);
+#endif /* __BIONIC_AVAILABILITY_GUARD(28) */
+
 int pthread_mutexattr_init(pthread_mutexattr_t* _Nonnull __attr);
 int pthread_mutexattr_setpshared(pthread_mutexattr_t* _Nonnull __attr, int __shared);
 int pthread_mutexattr_settype(pthread_mutexattr_t* _Nonnull __attr, int __type);
-int pthread_mutexattr_setprotocol(pthread_mutexattr_t* _Nonnull __attr, int __protocol) __INTRODUCED_IN(28);
 
+#if __BIONIC_AVAILABILITY_GUARD(28)
+int pthread_mutexattr_setprotocol(pthread_mutexattr_t* _Nonnull __attr, int __protocol) __INTRODUCED_IN(28);
+#endif /* __BIONIC_AVAILABILITY_GUARD(28) */
+
+
+
+#if __BIONIC_AVAILABILITY_GUARD(30)
 int pthread_mutex_clocklock(pthread_mutex_t* _Nonnull __mutex, clockid_t __clock,
                             const struct timespec* _Nullable __abstime) __INTRODUCED_IN(30);
+#endif /* __BIONIC_AVAILABILITY_GUARD(30) */
+
 int pthread_mutex_destroy(pthread_mutex_t* _Nonnull __mutex);
 int pthread_mutex_init(pthread_mutex_t* _Nonnull __mutex, const pthread_mutexattr_t* _Nullable __attr);
 int pthread_mutex_lock(pthread_mutex_t* _Nonnull __mutex);
@@ -210,8 +238,12 @@
  * Note that pthread_mutex_clocklock() allows specifying an arbitrary clock and has superseded this
  * function.
  */
+
+#if __BIONIC_AVAILABILITY_GUARD(28)
 int pthread_mutex_timedlock_monotonic_np(pthread_mutex_t* _Nonnull __mutex, const struct timespec* _Nullable __timeout)
     __INTRODUCED_IN(28);
+#endif /* __BIONIC_AVAILABILITY_GUARD(28) */
+
 int pthread_mutex_trylock(pthread_mutex_t* _Nonnull __mutex);
 int pthread_mutex_unlock(pthread_mutex_t* _Nonnull __mutex);
 
@@ -221,30 +253,48 @@
 int pthread_rwlockattr_destroy(pthread_rwlockattr_t* _Nonnull __attr);
 int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t* _Nonnull __attr, int* _Nonnull __shared);
 int pthread_rwlockattr_setpshared(pthread_rwlockattr_t* _Nonnull __attr, int __shared);
+
+#if __BIONIC_AVAILABILITY_GUARD(23)
 int pthread_rwlockattr_getkind_np(const pthread_rwlockattr_t* _Nonnull __attr, int* _Nonnull __kind)
   __INTRODUCED_IN(23);
 int pthread_rwlockattr_setkind_np(pthread_rwlockattr_t* _Nonnull __attr, int __kind) __INTRODUCED_IN(23);
+#endif /* __BIONIC_AVAILABILITY_GUARD(23) */
 
+
+
+#if __BIONIC_AVAILABILITY_GUARD(30)
 int pthread_rwlock_clockrdlock(pthread_rwlock_t* _Nonnull __rwlock, clockid_t __clock,
                                const struct timespec* _Nullable __timeout) __INTRODUCED_IN(30);
 int pthread_rwlock_clockwrlock(pthread_rwlock_t* _Nonnull __rwlock, clockid_t __clock,
                                const struct timespec* _Nullable __timeout) __INTRODUCED_IN(30);
+#endif /* __BIONIC_AVAILABILITY_GUARD(30) */
+
 int pthread_rwlock_destroy(pthread_rwlock_t* _Nonnull __rwlock);
 int pthread_rwlock_init(pthread_rwlock_t* _Nonnull __rwlock, const pthread_rwlockattr_t* _Nullable __attr);
 int pthread_rwlock_rdlock(pthread_rwlock_t* _Nonnull __rwlock);
 int pthread_rwlock_timedrdlock(pthread_rwlock_t* _Nonnull __rwlock, const struct timespec* _Nullable __timeout);
 /* See the comment on pthread_mutex_timedlock_monotonic_np for usage of this function. */
+
+#if __BIONIC_AVAILABILITY_GUARD(28)
 int pthread_rwlock_timedrdlock_monotonic_np(pthread_rwlock_t* _Nonnull __rwlock,
                                             const struct timespec* _Nullable __timeout) __INTRODUCED_IN(28);
+#endif /* __BIONIC_AVAILABILITY_GUARD(28) */
+
 int pthread_rwlock_timedwrlock(pthread_rwlock_t* _Nonnull __rwlock, const struct timespec* _Nullable __timeout);
 /* See the comment on pthread_mutex_timedlock_monotonic_np for usage of this function. */
+
+#if __BIONIC_AVAILABILITY_GUARD(28)
 int pthread_rwlock_timedwrlock_monotonic_np(pthread_rwlock_t* _Nonnull __rwlock,
                                             const struct timespec* _Nullable __timeout) __INTRODUCED_IN(28);
+#endif /* __BIONIC_AVAILABILITY_GUARD(28) */
+
 int pthread_rwlock_tryrdlock(pthread_rwlock_t* _Nonnull __rwlock);
 int pthread_rwlock_trywrlock(pthread_rwlock_t* _Nonnull __rwlock);
 int pthread_rwlock_unlock(pthread_rwlock_t* _Nonnull __rwlock);
 int pthread_rwlock_wrlock(pthread_rwlock_t* _Nonnull __rwlock);
 
+
+#if __BIONIC_AVAILABILITY_GUARD(24)
 int pthread_barrierattr_init(pthread_barrierattr_t* _Nonnull __attr) __INTRODUCED_IN(24);
 int pthread_barrierattr_destroy(pthread_barrierattr_t* _Nonnull __attr) __INTRODUCED_IN(24);
 int pthread_barrierattr_getpshared(const pthread_barrierattr_t* _Nonnull __attr, int* _Nonnull __shared) __INTRODUCED_IN(24);
@@ -259,11 +309,17 @@
 int pthread_spin_lock(pthread_spinlock_t* _Nonnull __spinlock) __INTRODUCED_IN(24);
 int pthread_spin_trylock(pthread_spinlock_t* _Nonnull __spinlock) __INTRODUCED_IN(24);
 int pthread_spin_unlock(pthread_spinlock_t* _Nonnull __spinlock) __INTRODUCED_IN(24);
+#endif /* __BIONIC_AVAILABILITY_GUARD(24) */
+
 
 pthread_t pthread_self(void) __attribute_const__;
 
 #if defined(__USE_GNU)
+
+#if __BIONIC_AVAILABILITY_GUARD(26)
 int pthread_getname_np(pthread_t __pthread, char* _Nonnull __buf, size_t __n) __INTRODUCED_IN(26);
+#endif /* __BIONIC_AVAILABILITY_GUARD(26) */
+
 #endif
 /* TODO: this should be __USE_GNU too. */
 int pthread_setname_np(pthread_t __pthread, const char* _Nonnull __name);
@@ -302,7 +358,11 @@
  *
  * Available since API level 28.
  */
+
+#if __BIONIC_AVAILABILITY_GUARD(28)
 int pthread_setschedprio(pthread_t __pthread, int __priority) __INTRODUCED_IN(28);
+#endif /* __BIONIC_AVAILABILITY_GUARD(28) */
+
 
 int pthread_setspecific(pthread_key_t __key, const void* _Nullable __value);