diff --git a/src/api/environment.cc b/src/api/environment.cc
index 766b603a313a3c..d00e719c725a45 100644
--- a/src/api/environment.cc
+++ b/src/api/environment.cc
@@ -351,9 +351,13 @@ Isolate* NewIsolate(ArrayBufferAllocator* allocator,
                     uv_loop_t* event_loop,
                     MultiIsolatePlatform* platform,
                     const EmbedderSnapshotData* snapshot_data,
-                    const IsolateSettings& settings) {
+                    const IsolateSettings& settings,
+                    std::unique_ptr<v8::CppHeap> cpp_heap) {
   Isolate::CreateParams params;
   if (allocator != nullptr) params.array_buffer_allocator = allocator;
+  if (cpp_heap) {
+    params.cpp_heap = cpp_heap.release();
+  }
   return NewIsolate(&params,
                     event_loop,
                     platform,
diff --git a/src/node.h b/src/node.h
index 06304fbdda9c32..eac0582d60620e 100644
--- a/src/node.h
+++ b/src/node.h
@@ -578,7 +578,8 @@ NODE_EXTERN v8::Isolate* NewIsolate(
     struct uv_loop_s* event_loop,
     MultiIsolatePlatform* platform,
     const EmbedderSnapshotData* snapshot_data = nullptr,
-    const IsolateSettings& settings = {});
+    const IsolateSettings& settings = {},
+    std::unique_ptr<v8::CppHeap> cpp_heap = {});
 NODE_EXTERN v8::Isolate* NewIsolate(
     std::shared_ptr<ArrayBufferAllocator> allocator,
     struct uv_loop_s* event_loop,
diff --git a/test/cctest/test_cppgc.cc b/test/cctest/test_cppgc.cc
index 350b7945c9e302..93673f77f3d6dc 100644
--- a/test/cctest/test_cppgc.cc
+++ b/test/cctest/test_cppgc.cc
@@ -46,18 +46,14 @@ int CppGCed::kDestructCount = 0;
 int CppGCed::kTraceCount = 0;
 
 TEST_F(NodeZeroIsolateTestFixture, ExistingCppHeapTest) {
-  v8::Isolate* isolate =
-      node::NewIsolate(allocator.get(), &current_loop, platform.get());
-
   // Create and attach the CppHeap before we set up the IsolateData so that
   // it recognizes the existing heap.
   std::unique_ptr<v8::CppHeap> cpp_heap =
       v8::CppHeap::Create(platform.get(), v8::CppHeapCreateParams{{}});
 
-  // TODO(joyeecheung): pass it into v8::Isolate::CreateParams and let V8
-  // own it when we can keep the isolate registered/task runner discoverable
-  // during isolate disposal.
-  isolate->AttachCppHeap(cpp_heap.get());
+  v8::Isolate* isolate =
+      node::NewIsolate(allocator.get(), &current_loop, platform.get(),
+      nullptr, {}, std::move(cpp_heap));
 
   // Try creating Context + IsolateData + Environment.
   {
@@ -102,8 +98,6 @@ TEST_F(NodeZeroIsolateTestFixture, ExistingCppHeapTest) {
     platform->DrainTasks(isolate);
 
     // Cleanup.
-    isolate->DetachCppHeap();
-    cpp_heap->Terminate();
     platform->DrainTasks(isolate);
   }