diff --git a/installer/arcline-installer b/installer/arcline-installer
index cde8629..416984c 100755
--- a/installer/arcline-installer
+++ b/installer/arcline-installer
@@ -125,8 +125,9 @@ class Installer(Gtk.Window):
 
         # boot mode
         self.boot_combo = Gtk.ComboBoxText()
-        for label, val in (("BIOS (grub-pc)", "bios"), ("UEFI (grub-efi-amd64)", "efi")):
-            self.boot_combo.append(label, val)
+        # ComboBoxText.append(id, text) — id is the value we pass to deploy
+        for val, label in (("bios", "BIOS (grub-pc)"), ("efi", "UEFI (grub-efi-amd64)")):
+            self.boot_combo.append(val, label)
         self.boot_combo.set_active(0)
         row_boot = Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL, spacing=8)
         row_boot.pack_start(Gtk.Label(label="Boot mode:"), False, False, 0)
diff --git a/scripts/deploy-disk.sh b/scripts/deploy-disk.sh
index f134f64..f97a50a 100755
--- a/scripts/deploy-disk.sh
+++ b/scripts/deploy-disk.sh
@@ -25,7 +25,16 @@ source "$(dirname "${BASH_SOURCE[0]}")/common.sh"
 DEV="${1:?usage: deploy-disk.sh <device> <rootfs> <edition> [--boot bios|efi]}"
 ROOTFS="${2:?usage: deploy-disk.sh <device> <rootfs> <edition> [--boot bios|efi]}"
 EDITION="${3:?usage: deploy-disk.sh <device> <rootfs> <edition> [--boot bios|efi]}"
-BOOT="${4:-$BOOT}"   # default from the BOOT build variable (see versions.mk)
+shift 3
+
+# Optional --boot <bios|efi> (a bare 4th positional is accepted too). Defaults
+# to the BOOT build variable (versions.mk / common.sh).
+BOOT="${BOOT:-bios}"
+if [[ $# -ge 2 && "$1" == "--boot" ]]; then
+  BOOT="$2"
+elif [[ $# -ge 1 ]]; then
+  BOOT="$1"
+fi
 
 require_root "$0" "$@"
 validate_edition "$EDITION"