diff --git a/target/linux/ar71xx/base-files/lib/upgrade/platform.sh b/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
index a76842bdde..eb812865db 100755
--- a/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/ar71xx/base-files/lib/upgrade/platform.sh
@@ -742,8 +742,13 @@ platform_do_upgrade_mikrotik_rb() {
 	local fw_mtd=$(find_mtd_part kernel)
 	fw_mtd="${fw_mtd/block/}"
 	[ -n "$fw_mtd" ] || return
+
+	local board_dir=$(tar tf "$1" | grep -m 1 '^sysupgrade-.*/$')
+	board_dir=${board_dir%/}
+	[ -n "$board_dir" ] || return
+
 	mtd erase kernel
-	tar xf "$1" sysupgrade-routerboard/kernel -O | nandwrite -o "$fw_mtd" -
+	tar xf "$1" ${board_dir}/kernel -O | nandwrite -o "$fw_mtd" -
 
 	nand_do_upgrade "$1"
 }