diff --git a/packer/initramfs/labsync b/packer/initramfs/labsync
index b9f20db..e8f4341 100755
--- a/packer/initramfs/labsync
+++ b/packer/initramfs/labsync
@@ -112,7 +112,7 @@ labsync_mount_root() {
 		labsync_info "Updating partitions"
 		size_disk=$(blockdev --getsz /dev/${labsync_disk})
 		size_part_1=$((labsync_partsize_boot * 1024 * 1024 / 512))
-		size_part_2=$(((size_disk - labsync_partsize_boot) * 1024 * 1024 / 512))
+		size_part_2=$((size_disk - size_part_1 - 2048))
 		start_part_2=$((size_part_1 + 2048))
 
 		dmsetup ls --tree