diff --git a/vhclient/rootfs/etc/s6-overlay/scripts/vhclient-use-devices b/vhclient/rootfs/etc/s6-overlay/scripts/vhclient-use-devices
index bdc26c2..5469c67 100755
--- a/vhclient/rootfs/etc/s6-overlay/scripts/vhclient-use-devices
+++ b/vhclient/rootfs/etc/s6-overlay/scripts/vhclient-use-devices
@@ -24,7 +24,7 @@ if bashio::config.has_value 'usbdevices'; then
 
     server_serial=$(/usr/bin/vh_server_serial_number ${deviceid%.*})
     device2=$(/usr/bin/vh_usb_product_vendor $deviceid)
-    deviceid2=$(server_serial.$device2)
+    deviceid2="${server_serial}.${device2}"
     bashio::log.info "GURKA-${deviceid2}"
 
     if $use; then