diff --git a/misc/script/flash.sh b/misc/script/flash.sh
index 5acb110..20503db 100755
--- a/misc/script/flash.sh
+++ b/misc/script/flash.sh
@@ -6,7 +6,8 @@ ssh-copy-id root@${OPENWRT_DEVICE}
 
 TARGET_ARCH=$(ssh root@${OPENWRT_DEVICE} source /etc/os-release \&\& echo \${OPENWRT_BOARD:-\$LEDE_BOARD})
 
-FIRMWARE_FILE=bin/${OPENWRT_VERSION}/${TARGET_ARCH}/${OPENWRT_PROFILE}/openwrt-*-sysupgrade.img*
+FIRMWARE_FILENAME=${FIRMWARE_FILENAME:-openwrt-*-sysupgrade.img*}
+FIRMWARE_FILE=bin/${OPENWRT_VERSION}/${TARGET_ARCH}/${OPENWRT_PROFILE}/${FIRMWARE_FILENAME}
 FIRMWARE_FILE=${CUSTOM_FIRMWARE_FILE:-$FIRMWARE_FILE}
 
 ssh root@${OPENWRT_DEVICE} \