diff --git a/pkgs/gf-pgf/default.nix b/pkgs/gf-pgf/default.nix
index ff4c1fa..012ffca 100644
--- a/pkgs/gf-pgf/default.nix
+++ b/pkgs/gf-pgf/default.nix
@@ -8,4 +8,5 @@ stdenv.mkDerivation {
   inherit (gf-core) version meta;
   src = "${gf-core.src}/src/runtime/c";
   nativeBuildInputs = [autoreconfHook ];
+  broken = true;
 }
diff --git a/pkgs/ljtools/default.nix b/pkgs/ljtools/default.nix
new file mode 100644
index 0000000..5c4c889
--- /dev/null
+++ b/pkgs/ljtools/default.nix
@@ -0,0 +1,28 @@
+{ qt5
+, luajit
+, stdenv
+, fetchFromGitHub
+  , GuiTools ? fetchFromGitHub {
+    owner = "rochus-keller";
+    repo = "GuiTools";
+    hash = "df36aa5c823d0c81259ae70b7c6f194c88017d6f";
+  }
+}:
+
+stdenv.mkDerivation {
+  pname = "ljtools";
+  src = fetchFromGitHub {
+    owner = "rochus-keller";
+    repo = "LjTools";
+    hash = "";
+    rev = "412675e2cc12bec1e00fd7a2ec52270f388d225b";
+  };
+  buildInputs = [
+    qt5.full
+    luajit
+  ];
+  nativeBuildInputs = [
+    qt5.full
+    luajit
+  ];
+}