diff --git a/libc/kernel/common/linux/hdlc/ioctl.h b/libc/kernel/common/linux/hdlc/ioctl.h
index c15a67f..ad1442c 100644
--- a/libc/kernel/common/linux/hdlc/ioctl.h
+++ b/libc/kernel/common/linux/hdlc/ioctl.h
@@ -7,51 +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 __HDLC_IOCTL_H__
 #define __HDLC_IOCTL_H__
-
 typedef struct {
  unsigned int clock_rate;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
  unsigned int clock_type;
  unsigned short loopback;
 } sync_serial_settings;
-
 typedef struct {
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
  unsigned int clock_rate;
  unsigned int clock_type;
  unsigned short loopback;
  unsigned int slot_map;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 } te1_settings;
-
 typedef struct {
  unsigned short encoding;
  unsigned short parity;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 } raw_hdlc_proto;
-
 typedef struct {
  unsigned int t391;
  unsigned int t392;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
  unsigned int n391;
  unsigned int n392;
  unsigned int n393;
  unsigned short lmi;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
  unsigned short dce;
 } fr_proto;
-
 typedef struct {
  unsigned int dlci;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 } fr_proto_pvc;
-
 typedef struct {
  unsigned int dlci;
  char master[IFNAMSIZ];
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 }fr_proto_pvc_info;
-
 typedef struct {
  unsigned int interval;
  unsigned int timeout;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 } cisco_proto;
-
 #endif