diff --git a/native_mate/object_template_builder.cc b/native_mate/object_template_builder.cc
index a8022158fb..7c40b58267 100644
--- a/native_mate/object_template_builder.cc
+++ b/native_mate/object_template_builder.cc
@@ -6,8 +6,10 @@
 
 namespace mate {
 
-ObjectTemplateBuilder::ObjectTemplateBuilder(v8::Isolate* isolate)
-    : isolate_(isolate), template_(v8::ObjectTemplate::New()) {
+ObjectTemplateBuilder::ObjectTemplateBuilder(
+    v8::Isolate* isolate,
+    v8::Local<v8::ObjectTemplate> templ)
+    : isolate_(isolate), template_(templ) {
   template_->SetInternalFieldCount(1);
 }
 
diff --git a/native_mate/object_template_builder.h b/native_mate/object_template_builder.h
index fb4be83242..cd69c47925 100644
--- a/native_mate/object_template_builder.h
+++ b/native_mate/object_template_builder.h
@@ -68,7 +68,9 @@ struct CallbackTraits<v8::Handle<v8::FunctionTemplate> > {
 // v8::ObjectTemplate instances with various sorts of properties.
 class ObjectTemplateBuilder {
  public:
-  explicit ObjectTemplateBuilder(v8::Isolate* isolate);
+  explicit ObjectTemplateBuilder(
+      v8::Isolate* isolate,
+      v8::Local<v8::ObjectTemplate> templ = v8::ObjectTemplate::New());
   ~ObjectTemplateBuilder();
 
   // It's against Google C++ style to return a non-const ref, but we take some