diff --git a/hosts/mobile-usb/usb_config.nix b/hosts/mobile-usb/usb_config.nix
index 90b6599..f995006 100644
--- a/hosts/mobile-usb/usb_config.nix
+++ b/hosts/mobile-usb/usb_config.nix
@@ -8,7 +8,7 @@
 
     boot.loader.grub.efiSupport = true;
     # location at install time. Since the drive is a USB drive this is expcected to change on each device
-    boot.loader.grub.device = "/dev/sdb";
+    boot.loader.grub.devices = ["/dev/sdb"];
     boot.loader.grub.efiInstallAsRemovable = true;
     boot.loader.systemd-boot.enable = false;