diff --git a/hardware-specific/onlykey.nix b/hardware-specific/onlykey.nix
new file mode 100644
index 0000000..d4b4e3c
--- /dev/null
+++ b/hardware-specific/onlykey.nix
@@ -0,0 +1,22 @@
+{ config, pkgs, ... }:
+{
+  assertions = [
+    {
+      assertion = config.users.users ? "vili";
+      message = "User 'vili' needed for onlykey!";
+    }
+  ];
+
+  environment.systemPackages = with pkgs; [
+    onlykey
+    onlykey-cli
+    onlykey-agent
+  ];
+
+  services.udev.extraRules = with pkgs; ''
+    ATTRS{idVendor}=="1d50", ATTRS{idProduct}=="60fc", ENV{ID_MM_DEVICE_IGNORE}="1"
+    ATTRS{idVendor}=="1d50", ATTRS{idProduct}=="60fc", ENV{MTP_NO_PROBE}="1"
+    SUBSYSTEMS=="usb", ATTRS{idVendor}=="1d50", ATTRS{idProduct}=="60fc", OWNER:="vili", RUN+="${onlykey-cli}/bin/onlykey-cli settime"
+    KERNEL=="ttyACM*", ATTRS{idVendor}=="1d50", ATTRS{idProduct}=="60fc", OWNER:="vili", RUN+="${onlykey-cli}/bin/onlykey-cli settime"
+  '';
+}
diff --git a/machine-confs/helium.nix b/machine-confs/helium.nix
index e5b7297..f707db4 100644
--- a/machine-confs/helium.nix
+++ b/machine-confs/helium.nix
@@ -76,6 +76,7 @@
     ../hardware-specific/trackball.nix
     ../hardware-specific/amd-laptop.nix
     ../hardware-specific/usb-automount.nix
+    ../hardware-specific/onlykey.nix
   ];
 
   services.xserver.displayManager.setupCommands = ''
diff --git a/machine-confs/lithium.nix b/machine-confs/lithium.nix
index 0e55e22..e4012a6 100644
--- a/machine-confs/lithium.nix
+++ b/machine-confs/lithium.nix
@@ -56,6 +56,7 @@
     ../hardware-specific/keychron-q11.nix
     ../hardware-specific/trackball.nix
     ../hardware-specific/usb-automount.nix
+    ../hardware-specific/onlykey.nix
   ];
 
   system.autoUpgrade.allowReboot = pkgs.lib.mkForce false;