diff --git a/libc/kernel/common/linux/patchkey.h b/libc/kernel/common/linux/patchkey.h
index fdf86ce..dc94949 100644
--- a/libc/kernel/common/linux/patchkey.h
+++ b/libc/kernel/common/linux/patchkey.h
@@ -7,25 +7,32 @@
  ***   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 _LINUX_PATCHKEY_H_INDIRECT
 #error "patchkey.h included directly"
 #endif
-
 #ifndef _LINUX_PATCHKEY_H
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define _LINUX_PATCHKEY_H
-
 #include <endian.h>
-
 #ifdef __BYTE_ORDER
 #if __BYTE_ORDER == __BIG_ENDIAN
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define _PATCHKEY(id) (0xfd00|id)
 #elif __BYTE_ORDER == __LITTLE_ENDIAN
 #define _PATCHKEY(id) ((id<<8)|0x00fd)
 #else
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #error "could not determine byte order"
 #endif
 #endif
-
 #endif
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */