diff --git a/libc/include/sys/mman.h b/libc/include/sys/mman.h
index 1a0e7f6..38cbf2f 100644
--- a/libc/include/sys/mman.h
+++ b/libc/include/sys/mman.h
@@ -133,7 +133,11 @@
  *
  * Returns 0 on success, and returns -1 and sets `errno` on failure.
  */
+
+#if __BIONIC_AVAILABILITY_GUARD(30)
 int mlock2(const void* _Nonnull __addr, size_t __size, int __flags) __INTRODUCED_IN(30);
+#endif /* __BIONIC_AVAILABILITY_GUARD(30) */
+
 
 /**
  * [munlock(2)](https://man7.org/linux/man-pages/man2/munlock.2.html)
@@ -171,7 +175,11 @@
  *
  * Returns the number of bytes advised on success, and returns -1 and sets `errno` on failure.
  */
+
+#if __BIONIC_AVAILABILITY_GUARD(31)
 ssize_t process_madvise(int __pid_fd, const struct iovec* _Nonnull __iov, size_t __count, int __advice, unsigned __flags) __INTRODUCED_IN(31);
+#endif /* __BIONIC_AVAILABILITY_GUARD(31) */
+
 
 #if defined(__USE_GNU)
 
@@ -183,7 +191,11 @@
  *
  * Returns an fd on success, and returns -1 and sets `errno` on failure.
  */
+
+#if __BIONIC_AVAILABILITY_GUARD(30)
 int memfd_create(const char* _Nonnull __name, unsigned __flags) __INTRODUCED_IN(30);
+#endif /* __BIONIC_AVAILABILITY_GUARD(30) */
+
 
 #endif
 
@@ -220,7 +232,11 @@
  *
  * Returns 0 on success, and returns a positive error number on failure.
  */
+
+#if __BIONIC_AVAILABILITY_GUARD(23)
 int posix_madvise(void* _Nonnull __addr, size_t __size, int __advice) __INTRODUCED_IN(23);
+#endif /* __BIONIC_AVAILABILITY_GUARD(23) */
+
 
 /**
  * [mseal(2)](https://man7.org/linux/man-pages/man2/mseal.2.html)
@@ -232,6 +248,10 @@
  *
  * Returns 0 on success, and returns -1 and sets `errno` on failure.
  */
+
+#if __BIONIC_AVAILABILITY_GUARD(36)
 int mseal(void* _Nonnull __addr, size_t __size, unsigned long __flags) __INTRODUCED_IN(36);
+#endif /* __BIONIC_AVAILABILITY_GUARD(36) */
+
 
 __END_DECLS