diff --git a/nixos/modules/services/x11/hardware/cmt.nix b/nixos/modules/services/x11/hardware/cmt.nix
index 95353e92098e..5ac824c5e419 100644
--- a/nixos/modules/services/x11/hardware/cmt.nix
+++ b/nixos/modules/services/x11/hardware/cmt.nix
@@ -47,7 +47,12 @@ in {
     assertions = [
       {
         assertion = !config.services.xserver.libinput.enable;
-        message = "cmt and libinput are incompatible, you cannot enable both (in services.xserver).";
+        message = ''
+          cmt and libinput are incompatible, meaning you cannot enable them both.
+          To use cmt you need to disable libinput with `services.xserver.libinput.enable = false`
+          If you haven't enabled it in configuration.nix, it's enabled by default on a
+          different xserver module.
+        '';
       }
     ];
   };