diff --git a/freecad-asm3.nix b/freecad-asm3.nix
new file mode 100644
index 0000000..cc973f0
--- /dev/null
+++ b/freecad-asm3.nix
@@ -0,0 +1,78 @@
+with import <nixpkgs> { }; let der =
+
+{ stdenv, mkDerivation, fetchFromGitHub, fetchpatch, cmake, ninja, coin3d,
+xercesc, ode, eigen, qtbase, qttools, qtwebengine, qtxmlpatterns, wrapQtAppsHook,
+opencascade-occt, gts, hdf5, vtk, medfile, zlib, python3Packages, swig,
+gfortran, libXmu, soqt, libf2c, libGLU, makeWrapper, pkgconfig, mpi ? null }:
+
+let
+  pythonPackages = python3Packages;
+in mkDerivation rec {
+  pname = "freecad-assembly3";
+  version = "0.11";
+
+  src = fetchFromGitHub {
+    owner = "realthunder";
+    repo = "FreeCAD";
+    rev = "asm3-${version}";
+    sha256 = "0q75xkvbzb9k25vg46m3ja10jlp2bbnl8zr6vk6skf928619ww1a";
+  };
+
+  nativeBuildInputs = [
+    cmake
+    ninja
+    pkgconfig
+    pythonPackages.pyside2-tools
+    wrapQtAppsHook
+  ];
+
+  buildInputs = [
+    cmake coin3d xercesc ode eigen opencascade-occt gts
+    zlib swig gfortran soqt libf2c makeWrapper mpi vtk hdf5 medfile
+    libGLU libXmu qtbase qttools qtwebengine qtxmlpatterns
+  ] ++ (with pythonPackages; [
+    matplotlib pycollada shiboken2 pyside2 pyside2-tools pivy python boost
+  ]);
+
+  cmakeFlags = [
+    "-DBUILD_QT5=ON"
+    "-DSHIBOKEN_INCLUDE_DIR=${pythonPackages.shiboken2}/include"
+    "-DSHIBOKEN_LIBRARY=Shiboken2::libshiboken"
+    ("-DPYSIDE_INCLUDE_DIR=${pythonPackages.pyside2}/include"
+      + ";${pythonPackages.pyside2}/include/PySide2/QtCore"
+      + ";${pythonPackages.pyside2}/include/PySide2/QtWidgets"
+      + ";${pythonPackages.pyside2}/include/PySide2/QtGui"
+      )
+    "-DPYSIDE_LIBRARY=PySide2::pyside2"
+  ];
+
+  # This should work on both x86_64, and i686 linux
+  preBuild = ''
+    export NIX_LDFLAGS="-L${gfortran.cc}/lib64 -L${gfortran.cc}/lib $NIX_LDFLAGS";
+  '';
+
+  # Their main() removes PYTHONPATH=, and we rely on it.
+  preConfigure = ''
+    sed '/putenv("PYTHONPATH/d' -i src/Main/MainGui.cpp
+
+    qtWrapperArgs+=(--prefix PYTHONPATH : "$PYTHONPATH")
+  '';
+
+  qtWrapperArgs = [
+    "--set COIN_GL_NO_CURRENT_CONTEXT_CHECK 1"
+  ];
+
+  postFixup = ''
+    mv $out/share/doc $out
+  '';
+
+  meta = with stdenv.lib; {
+    description = "General purpose Open Source 3D CAD/MCAD/CAx/CAE/PLM modeler";
+    homepage = "https://www.freecadweb.org/";
+    license = licenses.lgpl2Plus;
+    maintainers = with maintainers; [ viric gebner ];
+    platforms = platforms.linux;
+  };
+}
+
+; in libsForQt514.callPackage der { mpi = openmpi; }