diff --git a/libc/kernel/common/asm-generic/mman.h b/libc/kernel/common/asm-generic/mman.h
index 98d2783..d454921 100644
--- a/libc/kernel/common/asm-generic/mman.h
+++ b/libc/kernel/common/asm-generic/mman.h
@@ -7,40 +7,47 @@
  ***   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_GENERIC_MMAN_H
 #define _ASM_GENERIC_MMAN_H
-
 #define PROT_READ 0x1  
 #define PROT_WRITE 0x2  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define PROT_EXEC 0x4  
 #define PROT_SEM 0x8  
 #define PROT_NONE 0x0  
 #define PROT_GROWSDOWN 0x01000000  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define PROT_GROWSUP 0x02000000  
-
 #define MAP_SHARED 0x01  
 #define MAP_PRIVATE 0x02  
 #define MAP_TYPE 0x0f  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define MAP_FIXED 0x10  
 #define MAP_ANONYMOUS 0x20  
-
 #define MS_ASYNC 1  
 #define MS_INVALIDATE 2  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define MS_SYNC 4  
-
 #define MADV_NORMAL 0  
 #define MADV_RANDOM 1  
 #define MADV_SEQUENTIAL 2  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define MADV_WILLNEED 3  
 #define MADV_DONTNEED 4  
-
 #define MADV_REMOVE 9  
 #define MADV_DONTFORK 10  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define MADV_DOFORK 11  
-
 #define MAP_ANON MAP_ANONYMOUS
 #define MAP_FILE 0
-
 #endif
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */