diff --git a/default.nix b/default.nix
index 4cda275..b52b4a8 100644
--- a/default.nix
+++ b/default.nix
@@ -19,6 +19,8 @@ self: super:
 
   nghttp3-debug = super.enableDebugging self.nghttp3;
 
+  openmw-tes3mp = super.callPackage ./pkgs/openmw/tes3mp.nix { };
+
   picotls = super.callPackage ./pkgs/picotls/default.nix { };
 
   picoquic = super.callPackage ./pkgs/picoquic/default.nix { };
diff --git a/pkgs/openmw/tes3mp.nix b/pkgs/openmw/tes3mp.nix
new file mode 100644
index 0000000..1f97ca6
--- /dev/null
+++ b/pkgs/openmw/tes3mp.nix
@@ -0,0 +1,139 @@
+{ lib
+, stdenv
+, cmake
+, openmw
+, fetchFromGitHub
+, formats
+, luajit
+, makeWrapper
+, symlinkJoin
+, mygui
+, crudini
+}:
+
+# revisions are taken from https://github.com/GrimKriegor/TES3MP-deploy
+
+let
+  # raknet could also be split into dev and lib outputs
+  raknet = stdenv.mkDerivation {
+    pname = "raknet";
+    version = "unstable-2020-01-19";
+
+    src = fetchFromGitHub {
+      owner = "TES3MP";
+      repo = "CrabNet";
+      # usually fixed:
+      # https://github.com/GrimKriegor/TES3MP-deploy/blob/af49c67317258624debe1b5a9f8792f4cc3ad2d1/tes3mp-deploy.sh#L518
+      rev = "19e66190e83f53bcdcbcd6513238ed2e54878a21";
+      sha256 = "sha256-WIaJkSQnoOm9T7GoAwmWl7fNg79coIo/ILUsWcbH+lA=";
+    };
+
+    nativeBuildInputs = [ cmake ];
+
+    installPhase = ''
+      install -Dm555 lib/libRakNetLibStatic.a $out/lib/libRakNetLibStatic.a
+    '';
+  };
+
+  coreScripts = stdenv.mkDerivation {
+    pname = "corescripts";
+    version = "unstable-2022-10-21";
+
+    src = fetchFromGitHub {
+      owner = "TES3MP";
+      repo = "CoreScripts";
+      # usually latest in stable branch (e.g. 0.8.1)
+      rev = "6ae0a2a5d16171de3764817a7f8b1067ecde3def";
+      sha256 = "sha256-8j/Sr9IRMNFPEVfFzdb42PckHS3KW7FH7x7rRxIh5gY=";
+    };
+
+    buildCommand = ''
+      dir=$out/share/openmw-tes3mp
+      mkdir -p $dir
+      cp -r $src $dir/CoreScripts
+    '';
+  };
+
+  # build an unwrapped version so we don't have to rebuild it all over again in
+  # case the scripts or wrapper scripts change.
+  unwrapped = openmw.overrideAttrs (oldAttrs: rec {
+    pname = "tes3mp-unwrapped";
+    version = "0.8.1";
+
+    src = fetchFromGitHub {
+      owner = "TES3MP";
+      repo = "TES3MP";
+      # usually latest in stable branch (e.g. 0.8.1)
+      rev = "68954091c54d0596037c4fb54d2812313b7582a1";
+      sha256 = "sha256-8/bV4sw7Q8l8bDTHGQ0t4owf6J6h9q468JFx4KegY5o=";
+    };
+
+    nativeBuildInputs = oldAttrs.nativeBuildInputs ++ [ makeWrapper ];
+
+    buildInputs = oldAttrs.buildInputs ++ [ luajit ];
+
+    cmakeFlags = oldAttrs.cmakeFlags ++ [
+      "-DBUILD_OPENCS=OFF"
+      "-DRakNet_INCLUDES=${raknet.src}/include"
+      "-DRakNet_LIBRARY_RELEASE=${raknet}/lib/libRakNetLibStatic.a"
+      "-DRakNet_LIBRARY_DEBUG=${raknet}/lib/libRakNetLibStatic.a"
+    ];
+
+    prePatch = ''
+      substituteInPlace components/process/processinvoker.cpp \
+        --replace "\"./\"" "\"$out/bin/\""
+    '';
+
+    # https://github.com/TES3MP/openmw-tes3mp/issues/552
+    patches = oldAttrs.patches ++ [ ./tes3mp.patch ];
+
+    NIX_CFLAGS_COMPILE = "-fpermissive";
+
+    preConfigure = ''
+      substituteInPlace files/version.in \
+        --subst-var-by OPENMW_VERSION_COMMITHASH ${src.rev}
+    '';
+
+    # move everything that we wrap out of the way
+    postInstall = ''
+      mkdir -p $out/libexec
+      mv $out/bin/tes3mp-* $out/libexec
+    '';
+
+    meta = with lib; {
+      description = "Multiplayer for TES3:Morrowind based on OpenMW";
+      homepage = "https://tes3mp.com/";
+      license = licenses.gpl3Only;
+      maintainers = with maintainers; [ peterhoeg ];
+      platforms = [ "x86_64-linux" "i686-linux" ];
+    };
+  });
+
+  cfgFile = (formats.ini { }).generate "tes3mp-server.cfg" {
+    Plugins.home = "${coreScripts}/share/openmw-tes3mp/CoreScripts";
+  };
+
+in
+symlinkJoin rec {
+  name = "openmw-tes3mp-${unwrapped.version}";
+  inherit (unwrapped) version meta;
+
+  nativeBuildInputs = [ makeWrapper ];
+
+  paths = [ unwrapped ];
+
+  # crudini --merge will create the file if it doesn't exist
+  postBuild = ''
+    mkdir -p $out/bin
+
+    dir=\''${XDG_CONFIG_HOME:-\$HOME/.config}/openmw
+
+    makeWrapper ${unwrapped}/libexec/tes3mp-browser $out/bin/tes3mp-browser \
+      --chdir "$out/bin"
+
+    makeWrapper ${unwrapped}/libexec/tes3mp-server $out/bin/tes3mp-server \
+      --run "mkdir -p $dir" \
+      --run "${crudini}/bin/crudini --merge $dir/${cfgFile.name} < ${cfgFile}" \
+      --chdir "$out/bin"
+  '';
+}
diff --git a/pkgs/openmw/tes3mp.patch b/pkgs/openmw/tes3mp.patch
new file mode 100644
index 0000000..c2a78f9
--- /dev/null
+++ b/pkgs/openmw/tes3mp.patch
@@ -0,0 +1,13 @@
+diff --git a/apps/openmw-mp/Script/Types.hpp b/apps/openmw-mp/Script/Types.hpp
+index be365cfb8..204dcdc7b 100644
+--- a/apps/openmw-mp/Script/Types.hpp
++++ b/apps/openmw-mp/Script/Types.hpp
+@@ -105,7 +105,7 @@ struct ScriptFunctionPointer : public ScriptIdentity
+     void *addr;
+ #if (!defined(__clang__) && defined(__GNUC__))
+     template<typename R, typename... Types>
+-    constexpr ScriptFunctionPointer(Function<R, Types...> addr) : ScriptIdentity(addr), addr((void*)(addr)) {}
++    constexpr ScriptFunctionPointer(Function<R, Types...> addr) : ScriptIdentity(addr), addr(addr) {}
+ #else
+     template<typename R, typename... Types>
+     constexpr ScriptFunctionPointer(Function<R, Types...> addr) : ScriptIdentity(addr), addr(addr) {}