diff --git a/libc/private/bionic_auxv.h b/libc/private/bionic_auxv.h
index 69d15b6..23b2e37 100644
--- a/libc/private/bionic_auxv.h
+++ b/libc/private/bionic_auxv.h
@@ -29,6 +29,7 @@
 #define _PRIVATE_BIONIC_AUXV_H_
 
 #include <elf.h>
+#include <sys/cdefs.h>
 
 __BEGIN_DECLS
 
diff --git a/libc/private/bionic_futex.h b/libc/private/bionic_futex.h
index 6c7fdbe..69658b1 100644
--- a/libc/private/bionic_futex.h
+++ b/libc/private/bionic_futex.h
@@ -29,6 +29,7 @@
 #define _BIONIC_FUTEX_H
 
 #include <linux/futex.h>
+#include <sys/cdefs.h>
 
 __BEGIN_DECLS
 
diff --git a/libc/private/bionic_time.h b/libc/private/bionic_time.h
index 464ab0f..7c80f59 100644
--- a/libc/private/bionic_time.h
+++ b/libc/private/bionic_time.h
@@ -29,6 +29,7 @@
 #define _BIONIC_TIME_H
 
 #include <time.h>
+#include <sys/cdefs.h>
 
 __BEGIN_DECLS
 
diff --git a/libc/private/resolv_private.h b/libc/private/resolv_private.h
index 0f3c6c0..c43c84c 100644
--- a/libc/private/resolv_private.h
+++ b/libc/private/resolv_private.h
@@ -54,6 +54,8 @@
 #ifndef _RESOLV_PRIVATE_H_
 #define	_RESOLV_PRIVATE_H_
 
+#include <sys/cdefs.h>
+
 #include <resolv.h>
 #include "resolv_static.h"