diff --git a/modules/nixos/keyboard.nix b/modules/nixos/keyboard.nix
index e8991e2..bf23f9b 100644
--- a/modules/nixos/keyboard.nix
+++ b/modules/nixos/keyboard.nix
@@ -7,7 +7,7 @@ in
 {
   options.facter.detected.boot.keyboard.kernelModules = lib.mkOption {
     type = lib.types.listOf lib.types.str;
-    default = facterLib.collectDrivers (report.hardware.usb_controller or [ ]);
+    default = facterLib.stringSet (facterLib.collectDrivers (report.hardware.usb_controller or [ ]));
     example = [ "usbhid" ];
     description = ''
       List of kernel modules to include in the initrd to support the keyboard.