diff --git a/core/imgui/luajit_driver.cc b/core/imgui/luajit_driver.cc
index b061ba9..028c7ae 100644
--- a/core/imgui/luajit_driver.cc
+++ b/core/imgui/luajit_driver.cc
@@ -12,7 +12,15 @@ namespace nf7::core::imgui {
 
 std::shared_ptr<luajit::Value> LuaJITDriver::MakeExtensionObject(
     luajit::TaskContext& lua) {
-  lua_pushnil(*lua);
+  auto L = *lua;
+
+  lua_newuserdata(L, 0);
+  if (luaL_newmetatable(L, "nf7::core::imgui::LuaJITDriver::Extension")) {
+    lua_createtable(L, 0, 0);
+#   include "generated/imgui4lua.inc"
+    lua_setfield(L, -2, "__index");
+  }
+  lua_setmetatable(L, -2);
   return lua.Register();
 }
 
diff --git a/core/imgui/luajit_driver_test.cc b/core/imgui/luajit_driver_test.cc
index 1264229..34aa60e 100644
--- a/core/imgui/luajit_driver_test.cc
+++ b/core/imgui/luajit_driver_test.cc
@@ -38,12 +38,16 @@ TEST_F(ImGuiLuaJITDriver, CompileAndInstall) {
 
   auto fu = nf7::core::imgui::LuaJITDriver::CompileAndInstall(
       *subenv,
-      toVector("local ctx = ...\nctx:trace(\"hello world\")"),
+      toVector(
+          "local ctx = ...\nctx:trace(\"hello world\")\n"
+          "local imgui = ctx:recv():lua()\n"
+          "imgui.Begin(\"helloworld\", true, 0)\n"
+          "imgui.End()"),
       "test chunk");
 
   concurrency->Push(
       nf7::SyncTask {
-        clock->now() + std::chrono::seconds {2},
+        clock->now() + std::chrono::seconds {10},
         [&](auto&) { DropEnv(); },
       });
   ConsumeTasks();