diff --git a/modules/services/hardware/udev.nix b/modules/services/hardware/udev.nix
index 8c1a79f91282..f89f29222dc5 100644
--- a/modules/services/hardware/udev.nix
+++ b/modules/services/hardware/udev.nix
@@ -135,7 +135,7 @@ in
     
     hardware.firmware = mkOption {
       default = [];
-      example = [/root/my-firmware];
+      example = [ "/root/my-firmware" ];
       merge = mergeListOption; 
       description = ''
         List of directories containing firmware files.  Such files