diff --git a/ChangeLog b/ChangeLog
index a35843554..c388ebd27 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-05-31  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* disk/i386/pc/biosdisk.c (grub_biosdisk_open): Use
+	GRUB_DISK_SIZE_UNKNOWN.
+	* disk/ieee1275/ofdisk.c (grub_ofdisk_open): Likewise.
+
 2010-05-31  Jiro SEKIBA <jir@unicus.jp>
 
 	* include/grub/disk.h (GRUB_DISK_SIZE_UNKNOWN): New macro.
diff --git a/disk/i386/pc/biosdisk.c b/disk/i386/pc/biosdisk.c
index 94d0e3708..f82f91ff0 100644
--- a/disk/i386/pc/biosdisk.c
+++ b/disk/i386/pc/biosdisk.c
@@ -120,7 +120,8 @@ grub_biosdisk_open (const char *name, grub_disk_t disk)
     {
       data->flags = GRUB_BIOSDISK_FLAG_LBA | GRUB_BIOSDISK_FLAG_CDROM;
       data->sectors = 32;
-      total_sectors = GRUB_ULONG_MAX;  /* TODO: get the correct size.  */
+      /* TODO: get the correct size.  */
+      total_sectors = GRUB_DISK_SIZE_UNKNOWN;
     }
   else if (drive & 0x80)
     {
diff --git a/disk/ieee1275/ofdisk.c b/disk/ieee1275/ofdisk.c
index e5a4a67fa..d0d9e894f 100644
--- a/disk/ieee1275/ofdisk.c
+++ b/disk/ieee1275/ofdisk.c
@@ -204,7 +204,7 @@ grub_ofdisk_open (const char *name, grub_disk_t disk)
   /* XXX: There is no property to read the number of blocks.  There
      should be a property `#blocks', but it is not there.  Perhaps it
      is possible to use seek for this.  */
-  disk->total_sectors = 0xFFFFFFFFUL;
+  disk->total_sectors = GRUB_DISK_SIZE_UNKNOWN;
 
   disk->id = (unsigned long) op;