diff --git a/src/boot.sh b/src/boot.sh
index 0531414..c3598ad 100644
--- a/src/boot.sh
+++ b/src/boot.sh
@@ -6,6 +6,7 @@ set -Eeuo pipefail
 
 BOOT_OPTS=""
 BOOT_DESC=""
+DRIVER_TYPE="usb"
 SECURE=",secure=off"
 DIR="/usr/share/qemu"