diff --git a/target/linux/mediatek/mt7622/base-files/lib/upgrade/platform.sh b/target/linux/mediatek/mt7622/base-files/lib/upgrade/platform.sh
index 513741d6672..98775c6a134 100755
--- a/target/linux/mediatek/mt7622/base-files/lib/upgrade/platform.sh
+++ b/target/linux/mediatek/mt7622/base-files/lib/upgrade/platform.sh
@@ -13,15 +13,15 @@ platform_do_upgrade() {
 		case "$rootdev" in
 		mmc*)
 			blockdev --rereadpt /dev/$rootdev || return 1
-			local fitpart=$(get_partition_by_name $rootdev "production")
+			local fitpart=$(find_mmc_part "production" $rootdev)
 			[ "$fitpart" ] || return 1
-			dd if=/dev/zero of=/dev/$fitpart bs=4096 count=1 2>/dev/null
+			dd if=/dev/zero of=$fitpart bs=4096 count=1 2>/dev/null
 			blockdev --rereadpt /dev/$rootdev
-			get_image "$1" | dd of=/dev/$fitpart
+			get_image "$1" | dd of=$fitpart
 			blockdev --rereadpt /dev/$rootdev
-			local datapart=$(get_partition_by_name $rootdev "rootfs_data")
+			local datapart=$(find_mmc_part "rootfs_data" $rootdev)
 			[ "$datapart" ] || return 0
-			dd if=/dev/zero of=/dev/$datapart bs=4096 count=1 2>/dev/null
+			dd if=/dev/zero of=$datapart bs=4096 count=1 2>/dev/null
 			echo $datapart > /tmp/sysupgrade.datapart
 			;;
 		*)
@@ -95,7 +95,7 @@ platform_copy_config_mmc() {
 	[ -e "$UPGRADE_BACKUP" ] || return
 	local datapart=$(cat /tmp/sysupgrade.datapart)
 	[ "$datapart" ] || echo "no rootfs_data partition, cannot keep configuration." >&2
-	dd if="$UPGRADE_BACKUP" of=/dev/$datapart
+	dd if="$UPGRADE_BACKUP" of=$datapart
 	sync
 }