diff --git a/libc/kernel/arch-arm/asm/mtd-xip.h b/libc/kernel/arch-arm/asm/mtd-xip.h
index 6c53f6f..d6ce13f 100644
--- a/libc/kernel/arch-arm/asm/mtd-xip.h
+++ b/libc/kernel/arch-arm/asm/mtd-xip.h
@@ -7,14 +7,19 @@
  ***   structures, and macros generated from the original header, and thus,
  ***   contains no copyrightable information.
  ***
+ ***   To edit the content of this header, modify the corresponding
+ ***   source file (e.g. under external/kernel-headers/original/) then
+ ***   run bionic/libc/kernel/tools/update_all.py
+ ***
+ ***   Any manual change here will be lost the next time this script will
+ ***   be run. You've been warned!
+ ***
  ****************************************************************************
  ****************************************************************************/
 #ifndef __ARM_MTD_XIP_H__
 #define __ARM_MTD_XIP_H__
-
 #include <asm/hardware.h>
 #include <asm/arch/mtd-xip.h>
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define xip_iprefetch() do { asm volatile (".rep 8; nop; .endr"); } while (0)
-
 #endif