diff --git a/libc/kernel/common/mtd/mtd-user.h b/libc/kernel/common/mtd/mtd-user.h
index 1d37dc1..33cb632 100644
--- a/libc/kernel/common/mtd/mtd-user.h
+++ b/libc/kernel/common/mtd/mtd-user.h
@@ -7,19 +7,24 @@
  ***   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 __MTD_USER_H__
 #define __MTD_USER_H__
-
 #include <stdint.h>
-
 #include <mtd/mtd-abi.h>
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 typedef struct mtd_info_user mtd_info_t;
 typedef struct erase_info_user erase_info_t;
 typedef struct region_info_user region_info_t;
 typedef struct nand_oobinfo nand_oobinfo_t;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 typedef struct nand_ecclayout nand_ecclayout_t;
-
 #endif