diff --git a/CMakeLists.txt b/CMakeLists.txt
index 63e549b..a8940d1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
-project(UECS VERSION 0.9.2)
+project(UECS VERSION 0.9.3)
 message(STATUS "[Project] ${PROJECT_NAME}")
 
 include(FetchContent)
diff --git a/include/UECS/RTDCmptTraits.h b/include/UECS/RTDCmptTraits.h
index 8c140cc..501583b 100644
--- a/include/UECS/RTDCmptTraits.h
+++ b/include/UECS/RTDCmptTraits.h
@@ -40,6 +40,12 @@ namespace Ubpa {
 
 		inline RTDCmptTraits& Deregister(CmptType type) noexcept;
 
+		// register all for Cmpt
+		// static_assert
+		// - is_default_constructible_v
+		// - is_copy_constructible_v
+		// - is_move_constructible_v
+		// - is_destructible_v
 		template<typename Cmpt>
 		void Register();
 
diff --git a/include/UECS/detail/EntityMngr.inl b/include/UECS/detail/EntityMngr.inl
index 776cb98..473601d 100644
--- a/include/UECS/detail/EntityMngr.inl
+++ b/include/UECS/detail/EntityMngr.inl
@@ -115,7 +115,7 @@ namespace Ubpa {
 	template<typename... Cmpts>
 	std::tuple<Cmpts*...> EntityMngr::Attach(Entity e) {
 		static_assert((std::is_constructible_v<Cmpts> &&...),
-			"EntityMngr::Attach: <Cmpts> isn't default constructable");
+			"EntityMngr::Attach: <Cmpts> isn't default constructible");
 		if (!Exist(e)) throw std::invalid_argument("Entity is invalid");
 
 		using CmptList = TypeList<Cmpts...>;
diff --git a/include/UECS/detail/RTDCmptTraits.inl b/include/UECS/detail/RTDCmptTraits.inl
index 6d92bba..2625b0f 100644
--- a/include/UECS/detail/RTDCmptTraits.inl
+++ b/include/UECS/detail/RTDCmptTraits.inl
@@ -46,6 +46,7 @@ namespace Ubpa {
 
 	template<typename Cmpt>
 	void RTDCmptTraits::Register() {
+		static_assert(std::is_default_constructible_v<Cmpt>, "<Cmpt> must be default-constructible");
 		static_assert(std::is_copy_constructible_v<Cmpt>, "<Cmpt> must be copy-constructible");
 		static_assert(std::is_move_constructible_v<Cmpt>, "<Cmpt> must be move-constructible");
 		static_assert(std::is_destructible_v<Cmpt>, "<Cmpt> must be destructible");
@@ -55,6 +56,11 @@ namespace Ubpa {
 		sizeofs[type] = sizeof(Cmpt);
 		alignments[type] = alignof(Cmpt);
 
+		if constexpr (!std::is_trivially_default_constructible_v<Cmpt>) {
+			default_constructors[type] = [](void* cmpt) {
+				new(cmpt)Cmpt;
+			};
+		}
 		if constexpr (!std::is_trivially_destructible_v<Cmpt>) {
 			destructors[type] = [](void* cmpt) {
 				reinterpret_cast<Cmpt*>(cmpt)->~Cmpt();
@@ -79,6 +85,8 @@ namespace Ubpa {
 		sizeofs.erase(type);
 		alignments.erase(type);
 
+		if constexpr (!std::is_trivially_constructible_v<Cmpt>)
+			default_constructors.erase(type);
 		if constexpr (!std::is_trivially_destructible_v<Cmpt>)
 			destructors.erase(type);
 		if constexpr (!std::is_trivially_move_constructible_v<Cmpt>)
diff --git a/src/test/11_runtime_cmpt/main.cpp b/src/test/11_runtime_cmpt/main.cpp
index ae9cfc9..ccb35f2 100644
--- a/src/test/11_runtime_cmpt/main.cpp
+++ b/src/test/11_runtime_cmpt/main.cpp
@@ -50,7 +50,7 @@ int main() {
     // }
 	RTDCmptTraits::Instance().RegisterSize(type, 8);
 	RTDCmptTraits::Instance().RegisterDefaultConstructor(type, [](void*) { cout << "construct" << endl;});
-	RTDCmptTraits::Instance().RegisterDestructor(type, [](void*) { cout << "destructor" << endl; });
+	RTDCmptTraits::Instance().RegisterDestructor(type, [](void*) { cout << "destruct" << endl; });
 
 	World w;
 	w.systemMngr.Register<RTDSystem>();