diff --git a/libc/kernel/arch-x86/asm/tsc.h b/libc/kernel/arch-x86/asm/tsc.h
index 2528cd1..e99a1a5 100644
--- a/libc/kernel/arch-x86/asm/tsc.h
+++ b/libc/kernel/arch-x86/asm/tsc.h
@@ -7,16 +7,20 @@
  ***   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 _ASM_X86_TSC_H
 #define _ASM_X86_TSC_H
-
 #include <asm/processor.h>
-
 #define NS_SCALE 10  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define US_SCALE 32  
-
 typedef unsigned long long cycles_t;
-
 #endif