diff --git a/libc/kernel/arch-arm/asm/div64.h b/libc/kernel/arch-arm/asm/div64.h
index c03a0e4..6ba008a 100644
--- a/libc/kernel/arch-arm/asm/div64.h
+++ b/libc/kernel/arch-arm/asm/div64.h
@@ -7,21 +7,27 @@
  ***   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_ARM_DIV64
 #define __ASM_ARM_DIV64
-
 #include <asm/system.h>
-
 #ifdef __ARMEB__
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define __xh "r0"
 #define __xl "r1"
 #else
 #define __xl "r0"
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define __xh "r1"
 #endif
-
 #define do_div(n,base)  ({   register unsigned int __base asm("r4") = base;   register unsigned long long __n asm("r0") = n;   register unsigned long long __res asm("r2");   register unsigned int __rem asm(__xh);   asm( __asmeq("%0", __xh)   __asmeq("%1", "r2")   __asmeq("%2", "r0")   __asmeq("%3", "r4")   "bl	__do_div64"   : "=r" (__rem), "=r" (__res)   : "r" (__n), "r" (__base)   : "ip", "lr", "cc");   n = __res;   __rem;  })
-
 #endif
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */