diff --git a/buildroot-external/board/ova/post-image.sh b/buildroot-external/board/ova/post-image.sh
index c7035aba5..f48ea4740 100755
--- a/buildroot-external/board/ova/post-image.sh
+++ b/buildroot-external/board/ova/post-image.sh
@@ -1,32 +1,31 @@
 #!/bin/bash
 set -e
 
-SCRIPT_DIR="$BR2_EXTERNAL_HASSIO_PATH/scripts"
+SCRIPT_DIR=${BR2_EXTERNAL_HASSIO_PATH}/scripts
 BOARD_DIR="$(dirname $0)"
 
-OVERLAY_IMG="$BINARIES_DIR/overlay.ext4"
-DATA_IMG="$BINARIES_DIR/data.ext4"
-BOOT_IMG="$BINARIES_DIR/boot.vfat"
+OVERLAY_IMG=${BINARIES_DIR}/overlay.ext4
+DATA_IMG=${BINARIES_DIR}/data.ext4
+BOOT_IMG=${BINARIES_DIR}/boot.vfat
 
-BOOT_DATA="$BINARIES_DIR/boot-data"
+BOOT_DATA=${BINARIES_DIR}/boot-data
 
-. "$SCRIPT_DIR"/hdd_image.sh
+. ${SCRIPT_DIR}/hdd_image.sh
 
-rm -rf "$BOOT_DATA"
+rm -rf ${BOOT_DATA}
 
 # Init boot data
-mkdir -p "$BOOT_DATA/EFI/BOOT"
-mkdir -p "$BOOT_DATA/EFI/barebox"
+mkdir -p ${BOOT_DATA}/EFI/BOOT
+mkdir -p ${BOOT_DATA}/EFI/barebox
 
-cp "$BINARIES_DIR/barebox.bin" "$BOOT_DATA/EFI/BOOT/BOOTx64.EFI"
-cp "$BOARD_DIR/barebox-state.dtb" "$BOOT_DATA/EFI/barebox/state.dtb"
+cp ${BINARIES_DIR}/barebox.bin ${BOOT_DATA}/EFI/BOOT/BOOTx64.EFI
+cp ${BOARD_DIR}/barebox-state.dtb ${BOOT_DATA}/EFI/barebox/state.dtb
 
-hassio_boot_image "$BOOT_DATA" "$BOOT_IMG"
-hassio_overlay_image "$OVERLAY_IMG"
-hassio_data_image "$DATA_IMG"
+hassio_boot_image ${BOOT_DATA} ${BOOT_IMG}
+hassio_overlay_image ${OVERLAY_IMG}
+hassio_data_image ${DATA_IMG}
 
 
-hassio_hdd_image "$BOOT_IMG" "$BINARIES_DIR/rootfs.squashfs" "$OVERLAY_IMG" "$DATA_IMG" "$BINARIES_DIR/harddisk.img"
-
-qemu-img convert -O vmdk "$BINARIES_DIR/harddisk.img" "$BINARIES_DIR/hassio-os.vmdk"
+hassio_hdd_image ${BOOT_IMG} ${BINARIES_DIR}/rootfs.squashfs ${OVERLAY_IMG} ${DATA_IMG} ${BINARIES_DIR}/harddisk.img
 
+qemu-img convert -O vmdk ${BINARIES_DIR}/harddisk.img ${BINARIES_DIR}/hassio-os.vmdk