diff --git a/pkgs/tools/misc/timidity/default.nix b/pkgs/tools/misc/timidity/default.nix
index 1f0e68bb9c07..8c58e18e95f5 100644
--- a/pkgs/tools/misc/timidity/default.nix
+++ b/pkgs/tools/misc/timidity/default.nix
@@ -60,6 +60,7 @@ stdenv.mkDerivation rec {
   postInstall = ''
     mkdir -p $out/share/timidity/;
     cp ${./timidity.cfg} $out/share/timidity/timidity.cfg
+    substituteAllInPlace $out/share/timidity/timidity.cfg
     tar --strip-components=1 -xf $instruments -C $out/share/timidity/
   '';
   # This fixup step is unnecessary and fails on Darwin
diff --git a/pkgs/tools/misc/timidity/timidity.cfg b/pkgs/tools/misc/timidity/timidity.cfg
index fa07eb43eee6..f4a260d249e2 100644
--- a/pkgs/tools/misc/timidity/timidity.cfg
+++ b/pkgs/tools/misc/timidity/timidity.cfg
@@ -41,8 +41,7 @@
 # point to the library directory: 
 #
 
-dir /run/current-system/sw/share/timidity/instruments
-dir /run/current-system/sw/share/timidity/patch
+dir @out@/share/timidity
 
 ##############################################################################
 # This sets up the default patches in the TiMidity support package