diff --git a/atom/app/node_main.cc b/atom/app/node_main.cc
index 3111e9be39a..c1e8dd8aff4 100644
--- a/atom/app/node_main.cc
+++ b/atom/app/node_main.cc
@@ -46,7 +46,6 @@ int NodeMain(int argc, char *argv[]) {
     base::TaskScheduler::CreateAndStartWithDefaultParams("Electron");
 
     // Initialize gin::IsolateHolder.
-    JavascriptEnvironment::Initialize();
     JavascriptEnvironment gin_env;
 
     int exec_argc;
diff --git a/atom/browser/api/atom_api_app.cc b/atom/browser/api/atom_api_app.cc
index b35ffcbfc2b..39fd59612fa 100644
--- a/atom/browser/api/atom_api_app.cc
+++ b/atom/browser/api/atom_api_app.cc
@@ -529,8 +529,6 @@ void OnIconDataAvailable(v8::Isolate* isolate,
 }  // namespace
 
 App::App(v8::Isolate* isolate) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-
   static_cast<AtomBrowserClient*>(AtomBrowserClient::Get())->set_delegate(this);
   Browser::Get()->AddObserver(this);
   content::GpuDataManager::GetInstance()->AddObserver(this);
diff --git a/atom/browser/atom_browser_main_parts.cc b/atom/browser/atom_browser_main_parts.cc
index 8a6bc4278e1..cf3c96ac2c8 100644
--- a/atom/browser/atom_browser_main_parts.cc
+++ b/atom/browser/atom_browser_main_parts.cc
@@ -130,7 +130,27 @@ void AtomBrowserMainParts::PostEarlyInitialization() {
 
   // The ProxyResolverV8 has setup a complete V8 environment, in order to
   // avoid conflicts we only initialize our V8 environment after that.
-  JavascriptEnvironment::Initialize();
+  js_env_.reset(new JavascriptEnvironment);
+
+  node_bindings_->Initialize();
+
+  // Create the global environment.
+  node::Environment* env =
+      node_bindings_->CreateEnvironment(js_env_->context());
+  node_env_.reset(new NodeEnvironment(env));
+
+  // Enable support for v8 inspector
+  node_debugger_.reset(new NodeDebugger(env));
+  node_debugger_->Start();
+
+  // Add Electron extended APIs.
+  atom_bindings_->BindTo(js_env_->isolate(), env->process_object());
+
+  // Load everything.
+  node_bindings_->LoadEnvironment(env);
+
+  // Wrap the uv loop with global env.
+  node_bindings_->set_uv_env(env);
 }
 
 int AtomBrowserMainParts::PreCreateThreads() {
@@ -195,28 +215,6 @@ void AtomBrowserMainParts::PostMainMessageLoopStart() {
   base::FilePath user_dir;
   PathService::Get(brightray::DIR_USER_DATA, &user_dir);
   process_singleton_.reset(new ProcessSingleton(user_dir));
-
-  js_env_.reset(new JavascriptEnvironment);
-
-  node_bindings_->Initialize();
-
-  // Create the global environment.
-  node::Environment* env =
-      node_bindings_->CreateEnvironment(js_env_->context());
-  node_env_.reset(new NodeEnvironment(env));
-
-  // Enable support for v8 inspector
-  node_debugger_.reset(new NodeDebugger(env));
-  node_debugger_->Start();
-
-  // Add Electron extended APIs.
-  atom_bindings_->BindTo(js_env_->isolate(), env->process_object());
-
-  // Load everything.
-  node_bindings_->LoadEnvironment(env);
-
-  // Wrap the uv loop with global env.
-  node_bindings_->set_uv_env(env);
 }
 
 void AtomBrowserMainParts::PostMainMessageLoopRun() {
diff --git a/atom/browser/javascript_environment.cc b/atom/browser/javascript_environment.cc
index 2a22c344389..e7a510488a9 100644
--- a/atom/browser/javascript_environment.cc
+++ b/atom/browser/javascript_environment.cc
@@ -18,22 +18,9 @@
 
 namespace atom {
 
-// static
-void JavascriptEnvironment::Initialize() {
-  auto cmd = base::CommandLine::ForCurrentProcess();
-
-  // --js-flags.
-  std::string js_flags = cmd->GetSwitchValueASCII(switches::kJavaScriptFlags);
-  if (!js_flags.empty())
-    v8::V8::SetFlagsFromString(js_flags.c_str(), js_flags.size());
-
-  gin::IsolateHolder::Initialize(gin::IsolateHolder::kNonStrictMode,
-                                 gin::IsolateHolder::kStableV8Extras,
-                                 gin::ArrayBufferAllocator::SharedInstance());
-}
-
 JavascriptEnvironment::JavascriptEnvironment()
-    : isolate_holder_(base::ThreadTaskRunnerHandle::Get()),
+    : initialized_(Initialize()),
+      isolate_holder_(base::ThreadTaskRunnerHandle::Get()),
       isolate_(isolate_holder_.isolate()),
       isolate_scope_(isolate_),
       locker_(isolate_),
@@ -49,6 +36,21 @@ void JavascriptEnvironment::OnMessageLoopDestroying() {
   isolate_holder_.RemoveRunMicrotasksObserver();
 }
 
+bool JavascriptEnvironment::Initialize() {
+  auto cmd = base::CommandLine::ForCurrentProcess();
+
+  // --js-flags.
+  std::string js_flags = cmd->GetSwitchValueASCII(switches::kJavaScriptFlags);
+  if (!js_flags.empty())
+    v8::V8::SetFlagsFromString(js_flags.c_str(), js_flags.size());
+
+  gin::IsolateHolder::Initialize(gin::IsolateHolder::kNonStrictMode,
+                                 gin::IsolateHolder::kStableV8Extras,
+                                 gin::ArrayBufferAllocator::SharedInstance());
+
+  return true;
+}
+
 NodeEnvironment::NodeEnvironment(node::Environment* env) : env_(env) {
 }
 
diff --git a/atom/browser/javascript_environment.h b/atom/browser/javascript_environment.h
index 4a14caafbd4..e515307819c 100644
--- a/atom/browser/javascript_environment.h
+++ b/atom/browser/javascript_environment.h
@@ -18,8 +18,6 @@ namespace atom {
 // Manage the V8 isolate and context automatically.
 class JavascriptEnvironment {
  public:
-  static void Initialize();
-
   JavascriptEnvironment();
 
   void OnMessageLoopCreated();
@@ -32,6 +30,9 @@ class JavascriptEnvironment {
   }
 
  private:
+  bool Initialize();
+
+  bool initialized_;
   gin::IsolateHolder isolate_holder_;
   v8::Isolate* isolate_;
   v8::Isolate::Scope isolate_scope_;