diff --git a/pkgs/data/themes/material-kwin-decoration/default.nix b/pkgs/data/themes/material-kwin-decoration/default.nix
index f5dccefbc139..3716fb79368f 100644
--- a/pkgs/data/themes/material-kwin-decoration/default.nix
+++ b/pkgs/data/themes/material-kwin-decoration/default.nix
@@ -16,7 +16,7 @@
 
 mkDerivation rec {
   pname = "material-kwin-decoration";
-  version = "unstable-20211028";
+  version = "unstable-2021-10-28";
 
   src = fetchFromGitHub {
     owner = "Zren";
@@ -25,6 +25,11 @@ mkDerivation rec {
     sha256 = "sha256-aYlnPFhf+ISVe5Ycryu5BSXY8Lb5OoueMqnWQZiv6Lc=";
   };
 
+  postPatch = ''
+    substituteInPlace CMakeLists.txt \
+      --replace "-Werror" ""
+  '';
+
   nativeBuildInputs = [ cmake extra-cmake-modules ];
 
   buildInputs = [