diff --git a/pkgs/applications/video/key-mon/default.nix b/pkgs/applications/video/key-mon/default.nix
index 65de804ffa1..5b3c94ab271 100644
--- a/pkgs/applications/video/key-mon/default.nix
+++ b/pkgs/applications/video/key-mon/default.nix
@@ -1,5 +1,4 @@
-{ stdenv, fetchurl, buildPythonPackage, gnome, librsvg, makeWrapper, pygtk
-, pythonPackages }:
+{ stdenv, fetchurl, buildPythonPackage, gnome, librsvg, pygtk, pythonPackages }:
 
 buildPythonPackage rec {
   name = "key-mon-${version}";
@@ -12,14 +11,13 @@ buildPythonPackage rec {
   };
 
   propagatedBuildInputs =
-    [ gnome.python_rsvg librsvg makeWrapper pygtk pythonPackages.xlib ];
+    [ gnome.python_rsvg librsvg pygtk pythonPackages.xlib ];
 
   doCheck = false;
 
-  postInstall = ''
-      wrapProgram $out/bin/key-mon \
-          --set GDK_PIXBUF_MODULE_FILE "$GDK_PIXBUF_MODULE_FILE"
-    '';
+  makeWrapperArgs = ''
+    --set GDK_PIXBUF_MODULE_FILE ${librsvg}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache
+  '';
 
   meta = with stdenv.lib; {
     homepage = http://code.google.com/p/key-mon;