diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index 20fd566..ae4fdce 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -69,7 +69,9 @@
 
 #define PTHREAD_ONCE_INIT 0
 
+#if __ANDROID_API__ >= __ANDROID_API_N__
 #define PTHREAD_BARRIER_SERIAL_THREAD -1
+#endif
 
 #if defined(__LP64__)
 #define PTHREAD_STACK_MIN (4 * PAGE_SIZE)
@@ -178,23 +180,29 @@
 int pthread_rwlock_unlock(pthread_rwlock_t* _Nonnull);
 int pthread_rwlock_wrlock(pthread_rwlock_t* _Nonnull);
 
+#if __ANDROID_API__ >= __ANDROID_API_N__
 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 pshared) __INTRODUCED_IN(24);
 int pthread_barrierattr_setpshared(pthread_barrierattr_t* _Nonnull attr, int pshared)
   __INTRODUCED_IN(24);
+#endif
 
+#if __ANDROID_API__ >= __ANDROID_API_N__
 int pthread_barrier_init(pthread_barrier_t* _Nonnull, const pthread_barrierattr_t*, unsigned)
   __INTRODUCED_IN(24);
 int pthread_barrier_destroy(pthread_barrier_t* _Nonnull) __INTRODUCED_IN(24);
 int pthread_barrier_wait(pthread_barrier_t* _Nonnull) __INTRODUCED_IN(24);
+#endif
 
+#if __ANDROID_API__ >= __ANDROID_API_N__
 int pthread_spin_destroy(pthread_spinlock_t* _Nonnull) __INTRODUCED_IN(24);
 int pthread_spin_init(pthread_spinlock_t* _Nonnull, int) __INTRODUCED_IN(24);
 int pthread_spin_lock(pthread_spinlock_t* _Nonnull) __INTRODUCED_IN(24);
 int pthread_spin_trylock(pthread_spinlock_t* _Nonnull) __INTRODUCED_IN(24);
 int pthread_spin_unlock(pthread_spinlock_t* _Nonnull) __INTRODUCED_IN(24);
+#endif
 
 pthread_t pthread_self(void) __attribute_const__;