diff --git a/apps/machine/src/config/device.ts b/apps/machine/src/config/device.ts
index ae4ac00..cffdaa3 100644
--- a/apps/machine/src/config/device.ts
+++ b/apps/machine/src/config/device.ts
@@ -148,7 +148,12 @@ export const MACHINE_PRESETS: Record<MachineModel, Omit<DeviceConfig, 'fiatCode'
     },
     dispenser: {
       type: 'f56',
-      device: '/dev/ttyUSB0',
+      // Fujitsu F56 on a USB-serial bridge, via the stable udev symlink
+      // /dev/ttyF56 (batm3.nix, serial DDDLb103Y23). Avoids the raw
+      // /dev/ttyUSB0, which is enumeration-order dependent and could point at
+      // the wrong adapter after a re-plug/reboot. Per-box override:
+      // VITE_LAMASSU_DISPENSER_DEVICE.
+      device: '/dev/ttyF56',
       cassettes: [
         { denomination: 20, count: 400 },
         { denomination: 1, count: 400 },