diff --git a/libc/kernel/common/linux/pci.h b/libc/kernel/common/linux/pci.h
index 165deb4..cecaf07 100644
--- a/libc/kernel/common/linux/pci.h
+++ b/libc/kernel/common/linux/pci.h
@@ -7,23 +7,28 @@
  ***   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_PCI_H
 #define LINUX_PCI_H
-
 #include <linux/pci_regs.h>
-
 #include <linux/pci_ids.h>
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define PCI_DEVFN(slot,func) ((((slot) & 0x1f) << 3) | ((func) & 0x07))
 #define PCI_SLOT(devfn) (((devfn) >> 3) & 0x1f)
 #define PCI_FUNC(devfn) ((devfn) & 0x07)
-
 #define PCIIOC_BASE ('P' << 24 | 'C' << 16 | 'I' << 8)
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define PCIIOC_CONTROLLER (PCIIOC_BASE | 0x00)  
 #define PCIIOC_MMAP_IS_IO (PCIIOC_BASE | 0x01)  
 #define PCIIOC_MMAP_IS_MEM (PCIIOC_BASE | 0x02)  
 #define PCIIOC_WRITE_COMBINE (PCIIOC_BASE | 0x03)  
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif