diff --git a/deps/escargot b/deps/escargot
index 97e698db34..50aca7c2b4 160000
--- a/deps/escargot
+++ b/deps/escargot
@@ -1 +1 @@
-Subproject commit 97e698db347454bd11b7d58bae2d966f967739f1
+Subproject commit 50aca7c2b409f32e5f4c6fd7d7a53c53ae01f3d2
diff --git a/escargot.gyp b/escargot.gyp
index 06397e373b..50edc7117e 100755
--- a/escargot.gyp
+++ b/escargot.gyp
@@ -47,6 +47,7 @@
       'escargot_configs': [
         '-DESCARGOT_SMALL_CONFIG=1',
         '-DESCARGOT_USE_CUSTOM_LOGGING=ON',
+        '-DESCARGOT_USE_EXTENDED_API=ON',
         '-DESCARGOT_ARCH=<(target_arch)',
         '-DESCARGOT_HOST=<(build_host)',
         '-DESCARGOT_MODE=<(escargot_build_mode)',
diff --git a/src/api-data.cc b/src/api-data.cc
index 5d24ab5280..2044cd7370 100644
--- a/src/api-data.cc
+++ b/src/api-data.cc
@@ -2314,14 +2314,14 @@ void String::ExternalStringResourceBase::operator delete(void* ptr) {
 
 Local<Value> Symbol::Description() const {
   auto lwIsolate = IsolateWrap::GetCurrent();
-  auto esDescription = CVAL(this)->value()->asSymbol()->description();
-  return Utils::NewLocal<String>(lwIsolate->toV8(), esDescription.get());
+  auto esDescription = CVAL(this)->value()->asSymbol()->descriptionString();
+  return Utils::NewLocal<String>(lwIsolate->toV8(), esDescription);
 }
 
 Local<Value> Private::Name() const {
   auto lwIsolate = IsolateWrap::GetCurrent();
-  auto esDescription = CVAL(this)->value()->asSymbol()->description();
-  return Utils::NewLocal<String>(lwIsolate->toV8(), esDescription.get());
+  auto esDescription = CVAL(this)->value()->asSymbol()->descriptionString();
+  return Utils::NewLocal<String>(lwIsolate->toV8(), esDescription);
 }
 
 template <typename T, typename F>
diff --git a/src/api/es-helper.cc b/src/api/es-helper.cc
index bf94fe538e..0ec3a0ae3b 100755
--- a/src/api/es-helper.cc
+++ b/src/api/es-helper.cc
@@ -345,7 +345,10 @@ EvalResult ObjectRefHelper::setPrototype(ContextRef* context,
       [](ExecutionStateRef* state,
          ObjectRef* object,
          ValueRef* prototype) -> ValueRef* {
-        return ValueRef::create(object->setPrototype(state, prototype));
+        // call ObjectRef::setObjectPrototype instead of ObjectRef::setPrototype
+        // here because ImmutablePrototypeObject blocks __proto__ property
+        // setting
+        return ValueRef::create(object->setObjectPrototype(state, prototype));
       },
       object,
       prototype);
diff --git a/src/api/isolate.cc b/src/api/isolate.cc
index 81d820890f..6d45efb2ee 100755
--- a/src/api/isolate.cc
+++ b/src/api/isolate.cc
@@ -572,7 +572,7 @@ SymbolRef* IsolateWrap::createApiSymbol(StringRef* name) {
   auto newSymbol = SymbolRef::create(name);
   bool found = false;
   for (size_t i = 0; i < apiSymbols_.size(); i++) {
-    if (apiSymbols_[i]->description()->equals(name)) {
+    if (apiSymbols_[i]->descriptionString()->equals(name)) {
       apiSymbols_[i] = newSymbol;
       found = true;
       break;
@@ -592,7 +592,7 @@ SymbolRef* IsolateWrap::getApiSymbol(StringRef* name) {
   LWNODE_CALL_TRACE_ID(ISOWRAP);
 
   for (auto apiSymbols : apiSymbols_) {
-    if (apiSymbols->description()->equals(name)) {
+    if (apiSymbols->descriptionString()->equals(name)) {
       return apiSymbols;
     }
   }
@@ -605,7 +605,7 @@ SymbolRef* IsolateWrap::createApiPrivateSymbol(StringRef* name) {
   auto newSymbol = SymbolRef::create(name);
   bool found = false;
   for (size_t i = 0; i < apiPrivateSymbols_.size(); i++) {
-    if (apiPrivateSymbols_[i]->description()->equals(name)) {
+    if (apiPrivateSymbols_[i]->descriptionString()->equals(name)) {
       apiPrivateSymbols_[i] = newSymbol;
       found = true;
       break;
@@ -626,7 +626,7 @@ SymbolRef* IsolateWrap::getApiPrivateSymbol(StringRef* name) {
   LWNODE_CALL_TRACE_ID(ISOWRAP);
 
   for (auto apiPrivateSymbol : apiPrivateSymbols_) {
-    if (apiPrivateSymbol->description()->equals(name)) {
+    if (apiPrivateSymbol->descriptionString()->equals(name)) {
       return apiPrivateSymbol;
     }
   }