diff --git a/ChangeLog b/ChangeLog
index 3f6ace353..a12621577 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2009-07-15  Pavel Roskin  <proski@gnu.org>
 
+	* include/grub/disk.h (struct grub_disk_dev): Use enum for id.
+	* kern/disk.c (struct grub_disk_cache): Likewise.
+
 	* commands/probe.c (options): Typo fix.
 
 	* include/grub/i386/pc/boot.h (GRUB_BOOT_MACHINE_BPB_END):
diff --git a/include/grub/disk.h b/include/grub/disk.h
index a47e11337..5899e9425 100644
--- a/include/grub/disk.h
+++ b/include/grub/disk.h
@@ -56,7 +56,7 @@ struct grub_disk_dev
   const char *name;
 
   /* The device id used by the cache manager.  */
-  unsigned long id;
+  enum grub_disk_dev_id id;
 
   /* Call HOOK with each device name, until HOOK returns non-zero.  */
   int (*iterate) (int (*hook) (const char *name));
diff --git a/kern/disk.c b/kern/disk.c
index 0c54ed467..e167fb630 100644
--- a/kern/disk.c
+++ b/kern/disk.c
@@ -34,7 +34,7 @@ static grub_uint64_t grub_last_time = 0;
 /* Disk cache.  */
 struct grub_disk_cache
 {
-  unsigned long dev_id;
+  enum grub_disk_dev_id dev_id;
   unsigned long disk_id;
   grub_disk_addr_t sector;
   char *data;