diff --git a/board/czechlight/clearfog/boot.scr.txt b/board/czechlight/clearfog/boot.scr.txt
index bb48d89..efca0b6 100644
--- a/board/czechlight/clearfog/boot.scr.txt
+++ b/board/czechlight/clearfog/boot.scr.txt
@@ -1,6 +1,6 @@
 setenv bootargs root=/dev/mmcblk0p${rauc_part} rauc.slot=${rauc_slot} czechlight=${czechlight} systemd.machine_id=${machineid} panic=10 oops=panic
 setenv bootargs ${bootargs} spidev.bufsiz=65535
-if load mmc 0:${rauc_part} ${fdt_addr_r} /boot/${czechlight}-clearfog.dtb; then
+if test -n ${czechlight} && load mmc 0:${rauc_part} ${fdt_addr_r} /boot/${czechlight}-clearfog.dtb; then
   echo "DTS: ${czechlight}-clearfog"
 else
   load mmc 0:${rauc_part} ${fdt_addr_r} /boot/czechlight-clearfog.dtb || reset