diff --git a/libc/include/sys/sem.h b/libc/include/sys/sem.h
index 5682282..72f567e 100644
--- a/libc/include/sys/sem.h
+++ b/libc/include/sys/sem.h
@@ -51,12 +51,20 @@
   void* _Nullable __pad;
 };
 
+
+#if __BIONIC_AVAILABILITY_GUARD(26)
 int semctl(int __sem_id, int __sem_num, int __op, ...) __INTRODUCED_IN(26);
 int semget(key_t __key, int __sem_count, int __flags) __INTRODUCED_IN(26);
 int semop(int __sem_id, struct sembuf* _Nonnull __ops, size_t __op_count) __INTRODUCED_IN(26);
+#endif /* __BIONIC_AVAILABILITY_GUARD(26) */
+
 
 #if defined(__USE_GNU)
+
+#if __BIONIC_AVAILABILITY_GUARD(26)
 int semtimedop(int __sem_id, struct sembuf* _Nonnull __ops, size_t __op_count, const struct timespec* _Nullable __timeout) __INTRODUCED_IN(26);
+#endif /* __BIONIC_AVAILABILITY_GUARD(26) */
+
 #endif
 
 __END_DECLS