diff --git a/torch/csrc/jit/mobile/flatbuffer_loader.cpp b/torch/csrc/jit/mobile/flatbuffer_loader.cpp
index 0e126ff..4e6048e 100644
--- a/torch/csrc/jit/mobile/flatbuffer_loader.cpp
+++ b/torch/csrc/jit/mobile/flatbuffer_loader.cpp
@@ -123,29 +123,29 @@ FlatbufferLoader::FlatbufferLoader()
     : mcu_(std::make_shared<mobile::CompilationUnit>()),
       cu_(std::make_shared<CompilationUnit>()),
       ivalue_parsers_{nullptr} {
-  registerIValueParser(mobile::serialization::IValueUnion::NONE, &parseBasic);
-  registerIValueParser(mobile::serialization::IValueUnion::Int, &parseBasic);
-  registerIValueParser(mobile::serialization::IValueUnion::Bool, &parseBasic);
-  registerIValueParser(mobile::serialization::IValueUnion::Double, &parseBasic);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_NONE, &parseBasic);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_Int, &parseBasic);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_Bool, &parseBasic);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_Double, &parseBasic);
   registerIValueParser(
-      mobile::serialization::IValueUnion::ComplexDouble, &parseBasic);
+      mobile::serialization::IValueUnion::IValueUnion_ComplexDouble, &parseBasic);
   registerIValueParser(
-      mobile::serialization::IValueUnion::TensorMetadata, &parseTensor);
-  registerIValueParser(mobile::serialization::IValueUnion::String, &parseBasic);
-  registerIValueParser(mobile::serialization::IValueUnion::List, &parseList);
+      mobile::serialization::IValueUnion::IValueUnion_TensorMetadata, &parseTensor);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_String, &parseBasic);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_List, &parseList);
   registerIValueParser(
-      mobile::serialization::IValueUnion::IntList, &parseIntList);
+      mobile::serialization::IValueUnion::IValueUnion_IntList, &parseIntList);
   registerIValueParser(
-      mobile::serialization::IValueUnion::DoubleList, &parseDoubleList);
+      mobile::serialization::IValueUnion::IValueUnion_DoubleList, &parseDoubleList);
   registerIValueParser(
-      mobile::serialization::IValueUnion::BoolList, &parseBoolList);
-  registerIValueParser(mobile::serialization::IValueUnion::Tuple, &parseTuple);
-  registerIValueParser(mobile::serialization::IValueUnion::Dict, &parseDict);
+      mobile::serialization::IValueUnion::IValueUnion_BoolList, &parseBoolList);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_Tuple, &parseTuple);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_Dict, &parseDict);
   registerIValueParser(
-      mobile::serialization::IValueUnion::Object, &parseObject);
-  registerIValueParser(mobile::serialization::IValueUnion::Device, &parseBasic);
+      mobile::serialization::IValueUnion::IValueUnion_Object, &parseObject);
+  registerIValueParser(mobile::serialization::IValueUnion::IValueUnion_Device, &parseBasic);
   registerIValueParser(
-      mobile::serialization::IValueUnion::EnumValue, &parseEnum);
+      mobile::serialization::IValueUnion::IValueUnion_EnumValue, &parseEnum);
   internal_registerTypeResolver(&resolveType);
 }
 
@@ -334,21 +334,21 @@ IValue parseBasic(
     FlatbufferLoader&,
     const mobile::serialization::IValue& ivalue) {
   switch (ivalue.val_type()) {
-    case mobile::serialization::IValueUnion::NONE:
+    case mobile::serialization::IValueUnion::IValueUnion_NONE:
       return {};
-    case mobile::serialization::IValueUnion::Int:
+    case mobile::serialization::IValueUnion::IValueUnion_Int:
       return ivalue.val_as_Int()->int_val();
-    case mobile::serialization::IValueUnion::Bool:
+    case mobile::serialization::IValueUnion::IValueUnion_Bool:
       return ivalue.val_as_Bool()->bool_val();
-    case mobile::serialization::IValueUnion::Double:
+    case mobile::serialization::IValueUnion::IValueUnion_Double:
       return ivalue.val_as_Double()->double_val();
-    case mobile::serialization::IValueUnion::ComplexDouble: {
+    case mobile::serialization::IValueUnion::IValueUnion_ComplexDouble: {
       const auto* comp = ivalue.val_as_ComplexDouble();
       return c10::complex<double>(comp->real(), comp->imag());
     }
-    case mobile::serialization::IValueUnion::String:
+    case mobile::serialization::IValueUnion::IValueUnion_String:
       return ivalue.val_as_String()->data()->str();
-    case mobile::serialization::IValueUnion::Device: {
+    case mobile::serialization::IValueUnion::IValueUnion_Device: {
       return c10::Device(ivalue.val_as_Device()->str()->str());
     }
     default:
@@ -504,7 +504,7 @@ ClassTypePtr FlatbufferLoader::getOrCreateClassTypeForObject(
     TORCH_CHECK(object->type_index() < all_ivalues_.size());
     all_types_[object->type_index()] = cls;
 
-    if (obj_type->type() == mobile::serialization::TypeType::CLASS_WITH_FIELD) {
+    if (obj_type->type() == mobile::serialization::TypeType::TypeType_CLASS_WITH_FIELD) {
       for (uint32_t i = 0; i < object->attrs()->size(); i++) {
         IValue val = getIValue(object->attrs()->Get(i));
         // Need to use concrete object's field's type to set type of field.
@@ -529,7 +529,7 @@ IValue parseObject(
   auto cls = loader.getOrCreateClassTypeForObject(object);
   Stack stack;
   switch (obj_type->type()) {
-    case mobile::serialization::TypeType::CLASS_WITH_FIELD: {
+    case mobile::serialization::TypeType::TypeType_CLASS_WITH_FIELD: {
       auto obj = c10::ivalue::Object::create(
           at::StrongTypePtr(loader.cu_, cls), object->attrs()->size());
       for (uint32_t i = 0; i < object->attrs()->size(); i++) {
@@ -538,7 +538,7 @@ IValue parseObject(
       }
       return obj;
     }
-    case mobile::serialization::TypeType::CLASS_WITH_SETSTATE: {
+    case mobile::serialization::TypeType::TypeType_CLASS_WITH_SETSTATE: {
       IValue input = loader.getIValue(object->state());
       mobile::Function* setstate = loader.getFunction(object->setstate_func());
       auto obj =
@@ -548,7 +548,7 @@ IValue parseObject(
       setstate->run(stack);
       return obj;
     }
-    case mobile::serialization::TypeType::CUSTOM_CLASS: {
+    case mobile::serialization::TypeType::TypeType_CUSTOM_CLASS: {
       auto custom_class_type =
           torch::jit::getCustomClass(cls->name()->qualifiedName());
       IValue input = loader.getIValue(object->state());
diff --git a/torch/csrc/jit/mobile/flatbuffer_loader.h b/torch/csrc/jit/mobile/flatbuffer_loader.h
index 7e88326..dc95202 100644
--- a/torch/csrc/jit/mobile/flatbuffer_loader.h
+++ b/torch/csrc/jit/mobile/flatbuffer_loader.h
@@ -151,7 +151,7 @@ class TORCH_API FlatbufferLoader {
   std::vector<IValue> all_ivalues_;
   std::array<
       IValueParser,
-      static_cast<uint8_t>(mobile::serialization::IValueUnion::MAX) + 1>
+      static_cast<uint8_t>(mobile::serialization::IValueUnion::IValueUnion_MAX) + 1>
       ivalue_parsers_;
   TypeResolver type_resolver_ = nullptr;
   mobile::serialization::Module* module_ = nullptr;
diff --git a/torch/csrc/jit/serialization/flatbuffer_serializer.cpp b/torch/csrc/jit/serialization/flatbuffer_serializer.cpp
index 066a78c..a9e19bb 100644
--- a/torch/csrc/jit/serialization/flatbuffer_serializer.cpp
+++ b/torch/csrc/jit/serialization/flatbuffer_serializer.cpp
@@ -336,7 +336,7 @@ flatbuffers::DetachedBuffer FlatbufferSerializer::serializeModule(
   mcu_ = &module.compilation_unit();
 
   // first element is None.
-  insertIValue(CreateIValue(fbb, mobile::serialization::IValueUnion::NONE, 0));
+  insertIValue(CreateIValue(fbb, mobile::serialization::IValueUnion::IValueUnion_NONE, 0));
 
   auto methods = module.get_methods();
   std::vector<uint32_t> functions_index;
@@ -459,7 +459,7 @@ flatbuffers::Offset<mobile::serialization::Dict> FlatbufferSerializer::dictToFB(
 flatbuffers::Offset<mobile::serialization::ObjectType> FlatbufferSerializer::
     classTypeToFB(FlatBufferBuilder& fbb, ClassTypePtr class_ptr) {
   mobile::serialization::TypeType typetype =
-      mobile::serialization::TypeType::UNSET;
+      mobile::serialization::TypeType::TypeType_UNSET;
 
   flatbuffers::Offset<
       flatbuffers::Vector<flatbuffers::Offset<flatbuffers::String>>>
@@ -469,11 +469,11 @@ flatbuffers::Offset<mobile::serialization::ObjectType> FlatbufferSerializer::
   const mobile::Function* setstate = mcu_->find_function(setstate_name);
   const mobile::Function* getstate = mcu_->find_function(getstate_name);
   if (setstate != nullptr && getstate != nullptr) {
-    typetype = mobile::serialization::TypeType::CLASS_WITH_SETSTATE;
+    typetype = mobile::serialization::TypeType::TypeType_CLASS_WITH_SETSTATE;
   } else if (
       class_ptr->findMethod("__setstate__") &&
       class_ptr->findMethod("__getstate__")) {
-    typetype = mobile::serialization::TypeType::CUSTOM_CLASS;
+    typetype = mobile::serialization::TypeType::TypeType_CUSTOM_CLASS;
   } else {
     size_t num_attr = class_ptr->numAttributes();
     std::vector<flatbuffers::Offset<flatbuffers::String>> names;
@@ -482,7 +482,7 @@ flatbuffers::Offset<mobile::serialization::ObjectType> FlatbufferSerializer::
       names.push_back(fbb.CreateSharedString(class_ptr->getAttributeName(i)));
     }
     names_offset = fbb.CreateVector(names);
-    typetype = mobile::serialization::TypeType::CLASS_WITH_FIELD;
+    typetype = mobile::serialization::TypeType::TypeType_CLASS_WITH_FIELD;
   }
 
   auto name_offset = fbb.CreateString(class_ptr->name()->qualifiedName());
@@ -500,7 +500,7 @@ uint32_t FlatbufferSerializer::storeFunctionAndGetIndex(
 
   auto offset = CreateIValue(
       fbb,
-      mobile::serialization::IValueUnion::Function,
+      mobile::serialization::IValueUnion::IValueUnion_Function,
       functionToFB(fbb, qn, function).Union());
 
   uint32_t index = insertIValue(offset);
@@ -662,68 +662,68 @@ flatbuffers::Offset<mobile::serialization::IValue> FlatbufferSerializer::
     iValueToFB(flatbuffers::FlatBufferBuilder& fbb, const IValue& ivalue) {
   using mobile::serialization::IValueUnion;
 
-  IValueUnion ivalue_type = IValueUnion::NONE;
+  IValueUnion ivalue_type = IValueUnion::IValueUnion_NONE;
   flatbuffers::Offset<void> offset = 0;
 
   if (ivalue.isTensor()) {
-    ivalue_type = IValueUnion::TensorMetadata;
+    ivalue_type = IValueUnion::IValueUnion_TensorMetadata;
     offset = tensorToFB(fbb, ivalue).Union();
   } else if (ivalue.isTuple()) {
-    ivalue_type = IValueUnion::Tuple;
+    ivalue_type = IValueUnion::IValueUnion_Tuple;
     offset = tupleToFB(fbb, ivalue).Union();
   } else if (ivalue.isDouble()) {
-    ivalue_type = IValueUnion::Double;
+    ivalue_type = IValueUnion::IValueUnion_Double;
     offset = fbb.CreateStruct(mobile::serialization::Double(ivalue.toDouble()))
                  .Union();
   } else if (ivalue.isComplexDouble()) {
     auto comp = ivalue.toComplexDouble();
-    ivalue_type = IValueUnion::ComplexDouble;
+    ivalue_type = IValueUnion::IValueUnion_ComplexDouble;
     offset = fbb.CreateStruct(mobile::serialization::ComplexDouble(
                                   comp.real(), comp.imag()))
                  .Union();
   } else if (ivalue.isInt()) {
-    ivalue_type = IValueUnion::Int;
+    ivalue_type = IValueUnion::IValueUnion_Int;
     offset =
         fbb.CreateStruct(mobile::serialization::Int(ivalue.toInt())).Union();
   } else if (ivalue.isBool()) {
-    ivalue_type = IValueUnion::Bool;
+    ivalue_type = IValueUnion::IValueUnion_Bool;
     offset =
         fbb.CreateStruct(mobile::serialization::Bool(ivalue.toBool())).Union();
   } else if (ivalue.isString()) {
-    ivalue_type = IValueUnion::String;
+    ivalue_type = IValueUnion::IValueUnion_String;
     offset = mobile::serialization::CreateString(
                  fbb, fbb.CreateSharedString(ivalue.toString()->string()))
                  .Union();
   } else if (ivalue.isGenericDict()) {
-    ivalue_type = IValueUnion::Dict;
+    ivalue_type = IValueUnion::IValueUnion_Dict;
     offset = dictToFB(fbb, ivalue).Union();
   } else if (ivalue.isNone()) {
-    ivalue_type = IValueUnion::NONE;
+    ivalue_type = IValueUnion::IValueUnion_NONE;
     offset = 0;
   } else if (ivalue.isIntList()) {
-    ivalue_type = IValueUnion::IntList;
+    ivalue_type = IValueUnion::IValueUnion_IntList;
     offset = mobile::serialization::CreateIntList(
                  fbb, fbb.CreateVector(ivalue.toIntVector()))
                  .Union();
   } else if (ivalue.isDoubleList()) {
-    ivalue_type = IValueUnion::DoubleList;
+    ivalue_type = IValueUnion::IValueUnion_DoubleList;
     offset = mobile::serialization::CreateDoubleList(
                  fbb, fbb.CreateVector(ivalue.toDoubleVector()))
                  .Union();
   } else if (ivalue.isBoolList()) {
-    ivalue_type = IValueUnion::BoolList;
+    ivalue_type = IValueUnion::IValueUnion_BoolList;
     auto boollist = ivalue.toBoolList();
     std::vector<uint8_t> bool_vec(boollist.begin(), boollist.end());
     offset =
         mobile::serialization::CreateBoolListDirect(fbb, &bool_vec).Union();
   } else if (ivalue.isList()) {
-    ivalue_type = IValueUnion::List;
+    ivalue_type = IValueUnion::IValueUnion_List;
     offset = listToFB(fbb, ivalue).Union();
   } else if (ivalue.isObject()) {
-    ivalue_type = IValueUnion::Object;
+    ivalue_type = IValueUnion::IValueUnion_Object;
     offset = objectToFB(fbb, ivalue).Union();
   } else if (ivalue.isDevice()) {
-    ivalue_type = IValueUnion::Device;
+    ivalue_type = IValueUnion::IValueUnion_Device;
     offset = mobile::serialization::CreateDevice(
                  fbb, fbb.CreateSharedString(ivalue.toDevice().str()))
                  .Union();
@@ -732,7 +732,7 @@ flatbuffers::Offset<mobile::serialization::IValue> FlatbufferSerializer::
     const auto& qualified_class_name =
         enum_holder->type()->qualifiedClassName();
     uint32_t ival_pos = storeIValueAndGetIndex(fbb, enum_holder->value());
-    ivalue_type = IValueUnion::EnumValue;
+    ivalue_type = IValueUnion::IValueUnion_EnumValue;
     offset = mobile::serialization::CreateEnumValue(
                  fbb,
                  fbb.CreateSharedString(qualified_class_name.qualifiedName()),