diff --git a/include/image.mk b/include/image.mk
index 605474ce99..66ac497849 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -132,14 +132,12 @@ endif
 # $(1): board name
 # $(2): kernel image
 # $(3): rootfs image
-# $(4): ubi image
 ifneq ($(CONFIG_NAND_SUPPORT),)
    define Image/Build/SysupgradeNAND
 	mkdir -p $(KDIR_TMP)/sysupgrade-$(1)/
 	echo "BOARD=$(1)" > $(KDIR_TMP)/sysupgrade-$(1)/CONTROL
 	[ -z "$(2)" ] || $(CP) $(2) $(KDIR_TMP)/sysupgrade-$(1)/kernel
 	[ -z "$(3)" ] || $(CP) $(3) $(KDIR_TMP)/sysupgrade-$(1)/root
-	[ -z "$(4)" ] || $(CP) $(4) $(KDIR_TMP)/sysupgrade-$(1)/ubi
 	(cd $(KDIR_TMP); $(TAR) cvf \
 		$(BIN_DIR)/$(IMG_PREFIX)-$(1)-ubi-sysupgrade.tar sysupgrade-$(1))
    endef
diff --git a/package/system/procd/files/nand.sh b/package/system/procd/files/nand.sh
index 0b58a0313d..9131ddaa7b 100644
--- a/package/system/procd/files/nand.sh
+++ b/package/system/procd/files/nand.sh
@@ -4,8 +4,6 @@
 
 . /lib/functions.sh
 
-# combined-image uses 64k blocks
-CI_BLKSZ=65536
 # 'data' partition on NAND contains UBI
 CI_UBIPART="ubi"
 
@@ -192,7 +190,7 @@ nand_upgrade_ubinized() {
 
 	if [ ! "$mtdnum" ]; then
 		echo "cannot find mtd device $CI_UBIPART"
-		return 1;
+		reboot -f
 	fi
 
 	local mtddev="/dev/mtd${mtdnum}"
@@ -212,10 +210,9 @@ nand_do_upgrade_stage2() {
 
 	local kernel_length=`(tar xf $tar_file sysupgrade-$board_name/kernel -O | wc -c) 2> /dev/null`
 	local rootfs_length=`(tar xf $tar_file sysupgrade-$board_name/root -O | wc -c) 2> /dev/null`
-	local ubi_length=`(tar xf $tar_file sysupgrade-$board_name/ubi -O | wc -c) 2> /dev/null`
-	
+
 	local rootfs_type="$(identify_tar "$tar_file" root)"
-	
+
 	local has_kernel=1
 	local has_env=0