diff --git a/libc/kernel/arch-arm/asm/cache.h b/libc/kernel/arch-arm/asm/cache.h
index be26423..ea94fdd 100644
--- a/libc/kernel/arch-arm/asm/cache.h
+++ b/libc/kernel/arch-arm/asm/cache.h
@@ -7,12 +7,18 @@
  ***   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 __ASMARM_CACHE_H
 #define __ASMARM_CACHE_H
-
 #define L1_CACHE_SHIFT 5
 #define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif