diff --git a/resources/scripts/build/boot/roms_helper b/resources/scripts/build/boot/roms_helper
index 8e1655a5..48ba85ea 100755
--- a/resources/scripts/build/boot/roms_helper
+++ b/resources/scripts/build/boot/roms_helper
@@ -487,6 +487,9 @@ mkUbootRom() {
 	target_uboot_config="${3}"
 	cbfstool_path="${4}"
 
+	target_ubootelf=""
+	target_ubdir=""
+
 	if [ "${target_uboot_config}" = "default" ]; then
 		target_ubdir="payload/u-boot/${board}"
 	else