diff --git a/disk/part_mac.h b/disk/part_mac.h
index 0340fe8..fb1edac 100644
--- a/disk/part_mac.h
+++ b/disk/part_mac.h
@@ -89,6 +89,9 @@
 	__u32	boot_cksum;	/* boot code checksum			*/
 	uchar	processor[16];	/* Type of Processor			*/
 	__u16	part_pad[188];	/* reserved				*/
+#ifdef CONFIG_ISO_PARTITION
+        uchar   iso_dummy[2048];/* Reservere enough room for an ISO partition block to fit */ 
+#endif
 } mac_partition_t;
 
 #define MAC_STATUS_BOOTABLE	8	/* partition is bootable */