diff --git a/microsoft/surface/default.nix b/microsoft/surface/default.nix
index 395e05d..1943157 100644
--- a/microsoft/surface/default.nix
+++ b/microsoft/surface/default.nix
@@ -4,7 +4,7 @@
   assertions = [
     {
       assertion = false;
-      message = "Importing microsoft/surface/ (default.nix) directly is deprecated! See microsoft/surface/OLD-BEHAVIOUR-DEPRECATED.md for more details.";
+      message = "Importing microsoft/surface/ (default.nix) directly is deprecated! See https://github.com/NixOS/nixos-hardware/blob/master/microsoft/surface/OLD-BEHAVIOUR-DEPRECATED.md for more details.";
     }
   ];
 }