diff --git a/pkgs/applications/science/logic/twelf/default.nix b/pkgs/applications/science/logic/twelf/default.nix
index 7d5724967c1..ca2422558e9 100644
--- a/pkgs/applications/science/logic/twelf/default.nix
+++ b/pkgs/applications/science/logic/twelf/default.nix
@@ -21,6 +21,9 @@ stdenv.mkDerivation rec {
     rsync -av bin/{*,.heap} $out/bin/
     bin/.mkexec ${smlnj}/bin/sml $out/ twelf-server twelf-server
 
+    substituteInPlace emacs/twelf-init.el \
+      --replace '(concat twelf-root "emacs")' '(concat twelf-root "share/emacs/site-lisp/twelf")'
+
     mkdir -p $out/share/emacs/site-lisp/twelf/
     rsync -av emacs/ $out/share/emacs/site-lisp/twelf/