diff --git a/overlays/surface.nix b/overlays/surface.nix
index bcac85c..d3b509e 100644
--- a/overlays/surface.nix
+++ b/overlays/surface.nix
@@ -2,10 +2,10 @@ final: prev:
 
 let
   libwacomPatchesCommit = "f811946d7d8bacb3b9ee75f08c150c435ad59331";
-  mkPatch = name: sha256: prev.fetchpatch {
-    name = "${name}.patch";
+  mkPatch = name: sha256: prev.fetchurl {
+    inherit sha256;
+
     url = "https://raw.githubusercontent.com/linux-surface/libwacom-surface/${libwacomPatchesCommit}/${name}.patch";
-    sha256 = sha256;
   };
 in {
   libwacom = prev.libwacom.overrideAttrs (old: rec {