diff --git a/libc/kernel/common/linux/futex.h b/libc/kernel/common/linux/futex.h
index 30f9e59..7630654 100644
--- a/libc/kernel/common/linux/futex.h
+++ b/libc/kernel/common/linux/futex.h
@@ -7,55 +7,59 @@
  ***   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_FUTEX_H
 #define _LINUX_FUTEX_H
-
 #include <linux/sched.h>
-
 #define FUTEX_WAIT 0
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define FUTEX_WAKE 1
 #define FUTEX_FD 2
 #define FUTEX_REQUEUE 3
 #define FUTEX_CMP_REQUEUE 4
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define FUTEX_WAKE_OP 5
 #define FUTEX_LOCK_PI 6
 #define FUTEX_UNLOCK_PI 7
 #define FUTEX_TRYLOCK_PI 8
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 struct robust_list {
  struct robust_list __user *next;
 };
-
 struct robust_list_head {
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
  struct robust_list list;
-
  long futex_offset;
-
  struct robust_list __user *list_op_pending;
 };
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define FUTEX_WAITERS 0x80000000
-
 #define FUTEX_OWNER_DIED 0x40000000
-
 #define FUTEX_TID_MASK 0x3fffffff
-
 #define ROBUST_LIST_LIMIT 2048
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define FUTEX_OP_SET 0  
 #define FUTEX_OP_ADD 1  
 #define FUTEX_OP_OR 2  
 #define FUTEX_OP_ANDN 3  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define FUTEX_OP_XOR 4  
 #define FUTEX_OP_OPARG_SHIFT 8  
 #define FUTEX_OP_CMP_EQ 0  
 #define FUTEX_OP_CMP_NE 1  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define FUTEX_OP_CMP_LT 2  
 #define FUTEX_OP_CMP_LE 3  
 #define FUTEX_OP_CMP_GT 4  
 #define FUTEX_OP_CMP_GE 5  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define FUTEX_OP(op, oparg, cmp, cmparg)   (((op & 0xf) << 28) | ((cmp & 0xf) << 24)   | ((oparg & 0xfff) << 12) | (cmparg & 0xfff))
 #endif