diff --git a/libc/kernel/common/asm-generic/signal.h b/libc/kernel/common/asm-generic/signal.h
index 226d99c..f106b38 100644
--- a/libc/kernel/common/asm-generic/signal.h
+++ b/libc/kernel/common/asm-generic/signal.h
@@ -7,33 +7,39 @@
  ***   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_SIGNAL_H
 #define __ASM_GENERIC_SIGNAL_H
-
 #include <linux/compiler.h>
-
 #ifndef SIG_BLOCK
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define SIG_BLOCK 0  
 #endif
 #ifndef SIG_UNBLOCK
 #define SIG_UNBLOCK 1  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif
 #ifndef SIG_SETMASK
 #define SIG_SETMASK 2  
 #endif
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #ifndef __ASSEMBLY__
 typedef void __signalfn_t(int);
 typedef __signalfn_t __user *__sighandler_t;
-
 typedef void __restorefn_t(void);
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 typedef __restorefn_t __user *__sigrestore_t;
-
 #define SIG_DFL ((__force __sighandler_t)0)  
 #define SIG_IGN ((__force __sighandler_t)1)  
 #define SIG_ERR ((__force __sighandler_t)-1)  
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif
-
 #endif