diff --git a/native_mate/dictionary.cc b/native_mate/dictionary.cc
index 1504f683f0..88bdefb1f7 100644
--- a/native_mate/dictionary.cc
+++ b/native_mate/dictionary.cc
@@ -7,7 +7,8 @@
 namespace mate {
 
 Dictionary::Dictionary(v8::Isolate* isolate)
-    : isolate_(isolate) {
+    : isolate_(isolate),
+      object_(v8::Object::New()) {
 }
 
 Dictionary::Dictionary(v8::Isolate* isolate,
diff --git a/native_mate/dictionary.h b/native_mate/dictionary.h
index 563916e459..333bae0f7a 100644
--- a/native_mate/dictionary.h
+++ b/native_mate/dictionary.h
@@ -24,7 +24,7 @@ namespace mate {
 //
 class Dictionary {
  public:
-  explicit Dictionary(v8::Isolate* isolate = NULL);
+  Dictionary(v8::Isolate* isolate = v8::Isolate::GetCurrent());
   Dictionary(v8::Isolate* isolate, v8::Handle<v8::Object> object);
   ~Dictionary();