diff --git a/libc/include/sys/random.h b/libc/include/sys/random.h
index be52bd9..0251176 100644
--- a/libc/include/sys/random.h
+++ b/libc/include/sys/random.h
@@ -50,7 +50,7 @@
  *
  * See also arc4random_buf() which is available in all API levels.
  */
-int getentropy(void* __buffer, size_t __buffer_size) __wur __INTRODUCED_IN(28);
+int getentropy(void* _Nonnull __buffer, size_t __buffer_size) __wur __INTRODUCED_IN(28);
 
 /**
  * [getrandom(2)](http://man7.org/linux/man-pages/man2/getrandom.2.html) fills the given buffer
@@ -62,6 +62,6 @@
  *
  * See also arc4random_buf() which is available in all API levels.
  */
-ssize_t getrandom(void* __buffer, size_t __buffer_size, unsigned int __flags) __wur __INTRODUCED_IN(28);
+ssize_t getrandom(void* _Nonnull __buffer, size_t __buffer_size, unsigned int __flags) __wur __INTRODUCED_IN(28);
 
 __END_DECLS