diff --git a/pkgs/desktops/gnome-2/platform/libgnome/default.nix b/pkgs/desktops/gnome-2/platform/libgnome/default.nix
index 1bffa6211dc..a9957c41ff5 100644
--- a/pkgs/desktops/gnome-2/platform/libgnome/default.nix
+++ b/pkgs/desktops/gnome-2/platform/libgnome/default.nix
@@ -11,9 +11,11 @@ stdenv.mkDerivation rec {
     sha256 = "197pnq8y0knqjhm2fg4j6hbqqm3qfzfnd0irhwxpk1b4hqb3kimj";
   };
 
-  outputs = [ "out" "dev" ];
-
   patches = [ ./new-glib.patch ];
+  /* There's a comment containing an invalid utf-8 sequence, breaking glib-mkenums. */
+  postPatch = "sed '/returns the true filename/d' -i libgnome/gnome-config.h";
+
+  outputs = [ "out" "dev" ];
 
   nativeBuildInputs = [ pkgconfig ];
   buildInputs = [ popt zlib intltool GConf gnome_vfs libcanberra libtool ];