diff --git a/pkgs/development/libraries/mps/default.nix b/pkgs/development/libraries/mps/default.nix
index 3cc6d9ce3510..fd6e5d60bf7b 100644
--- a/pkgs/development/libraries/mps/default.nix
+++ b/pkgs/development/libraries/mps/default.nix
@@ -16,17 +16,17 @@ stdenv.mkDerivation rec {
     hash = "sha256-3ql3jWLccgnQHKf23B1en+nJ9rxqmHcWd7aBr93YER0=";
   };
 
+  postPatch = ''
+    # Disable -Werror to avoid biuld failure on fresh toolchains like
+    # gcc-13.
+    substituteInPlace code/gc.gmk --replace-fail '-Werror ' ' '
+    substituteInPlace code/gp.gmk --replace-fail '-Werror ' ' '
+    substituteInPlace code/ll.gmk --replace-fail '-Werror ' ' '
+  '';
+
   nativeBuildInputs = [ autoreconfHook ];
   buildInputs = [ sqlite ];
 
-  # needed for 1.116.0 to build with gcc7
-  env.NIX_CFLAGS_COMPILE = toString [
-    "-Wno-implicit-fallthrough"
-    "-Wno-error=clobbered"
-    "-Wno-error=cast-function-type"
-  ];
-
-
   meta = {
     description = "A flexible memory management and garbage collection library";
     homepage    = "https://www.ravenbrook.com/project/mps";