diff --git a/pkgs/tools/graphics/graphviz/default.nix b/pkgs/tools/graphics/graphviz/default.nix
index 678744ad5bbc..c070a73d1f19 100644
--- a/pkgs/tools/graphics/graphviz/default.nix
+++ b/pkgs/tools/graphics/graphviz/default.nix
@@ -29,6 +29,10 @@ stdenv.mkDerivation rec {
     sed -e 's@am__append_5 *=.*@am_append_5 =@' -i lib/gvc/Makefile
   '';
 
+  postInstall = ''
+    sed -i 's|`which lefty`|"'$out'/bin/lefty"|' $out/bin/dotty
+  '';
+
   meta = {
     description = "A program for visualising graphs";
     homepage = http://www.graphviz.org/;