diff --git a/libc/kernel/common/linux/preempt.h b/libc/kernel/common/linux/preempt.h
index b703dd3..1c0f1fe 100644
--- a/libc/kernel/common/linux/preempt.h
+++ b/libc/kernel/common/linux/preempt.h
@@ -7,25 +7,29 @@
  ***   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_PREEMPT_H
 #define __LINUX_PREEMPT_H
-
 #include <linux/thread_info.h>
 #include <linux/linkage.h>
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define add_preempt_count(val) do { preempt_count() += (val); } while (0)
 #define sub_preempt_count(val) do { preempt_count() -= (val); } while (0)
-
 #define inc_preempt_count() add_preempt_count(1)
 #define dec_preempt_count() sub_preempt_count(1)
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define preempt_count() (current_thread_info()->preempt_count)
-
 #define preempt_disable() do { } while (0)
 #define preempt_enable_no_resched() do { } while (0)
 #define preempt_enable() do { } while (0)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define preempt_check_resched() do { } while (0)
-
 #endif