diff --git a/gdextension/gdextension_interface.h b/gdextension/gdextension_interface.h
index 765952cfe..7a8c67141 100644
--- a/gdextension/gdextension_interface.h
+++ b/gdextension/gdextension_interface.h
@@ -290,7 +290,7 @@ typedef struct {
 	GDExtensionClassGetVirtual get_virtual_func; // Queries a virtual function by name and returns a callback to invoke the requested virtual function.
 	GDExtensionClassGetRID get_rid_func;
 	void *class_userdata; // Per-class user data, later accessible in instance bindings.
-} GDExtensionClassCreationInfo; // Deprecated. Use GDExtensionClassCreationInfo2 instead.
+} GDExtensionClassCreationInfo; // Deprecated. Use GDExtensionClassCreationInfo3 instead.
 
 typedef struct {
 	GDExtensionBool is_virtual;
@@ -323,7 +323,41 @@ typedef struct {
 	GDExtensionClassCallVirtualWithData call_virtual_with_data_func;
 	GDExtensionClassGetRID get_rid_func;
 	void *class_userdata; // Per-class user data, later accessible in instance bindings.
-} GDExtensionClassCreationInfo2;
+} GDExtensionClassCreationInfo2; // Deprecated. Use GDExtensionClassCreationInfo3 instead.
+
+typedef struct {
+	GDExtensionBool is_virtual;
+	GDExtensionBool is_abstract;
+	GDExtensionBool is_exposed;
+	GDExtensionBool is_runtime;
+	GDExtensionClassSet set_func;
+	GDExtensionClassGet get_func;
+	GDExtensionClassGetPropertyList get_property_list_func;
+	GDExtensionClassFreePropertyList free_property_list_func;
+	GDExtensionClassPropertyCanRevert property_can_revert_func;
+	GDExtensionClassPropertyGetRevert property_get_revert_func;
+	GDExtensionClassValidateProperty validate_property_func;
+	GDExtensionClassNotification2 notification_func;
+	GDExtensionClassToString to_string_func;
+	GDExtensionClassReference reference_func;
+	GDExtensionClassUnreference unreference_func;
+	GDExtensionClassCreateInstance create_instance_func; // (Default) constructor; mandatory. If the class is not instantiable, consider making it virtual or abstract.
+	GDExtensionClassFreeInstance free_instance_func; // Destructor; mandatory.
+	GDExtensionClassRecreateInstance recreate_instance_func;
+	// Queries a virtual function by name and returns a callback to invoke the requested virtual function.
+	GDExtensionClassGetVirtual get_virtual_func;
+	// Paired with `call_virtual_with_data_func`, this is an alternative to `get_virtual_func` for extensions that
+	// need or benefit from extra data when calling virtual functions.
+	// Returns user data that will be passed to `call_virtual_with_data_func`.
+	// Returning `NULL` from this function signals to Godot that the virtual function is not overridden.
+	// Data returned from this function should be managed by the extension and must be valid until the extension is deinitialized.
+	// You should supply either `get_virtual_func`, or `get_virtual_call_data_func` with `call_virtual_with_data_func`.
+	GDExtensionClassGetVirtualCallData get_virtual_call_data_func;
+	// Used to call virtual functions when `get_virtual_call_data_func` is not null.
+	GDExtensionClassCallVirtualWithData call_virtual_with_data_func;
+	GDExtensionClassGetRID get_rid_func;
+	void *class_userdata; // Per-class user data, later accessible in instance bindings.
+} GDExtensionClassCreationInfo3;
 
 typedef void *GDExtensionClassLibraryPtr;
 
@@ -2514,6 +2548,21 @@ typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClass)(GDExtensionCla
  */
 typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClass2)(GDExtensionClassLibraryPtr p_library, GDExtensionConstStringNamePtr p_class_name, GDExtensionConstStringNamePtr p_parent_class_name, const GDExtensionClassCreationInfo2 *p_extension_funcs);
 
+/**
+ * @name classdb_register_extension_class3
+ * @since 4.3
+ *
+ * Registers an extension class in the ClassDB.
+ *
+ * Provided struct can be safely freed once the function returns.
+ *
+ * @param p_library A pointer the library received by the GDExtension's entry point function.
+ * @param p_class_name A pointer to a StringName with the class name.
+ * @param p_parent_class_name A pointer to a StringName with the parent class name.
+ * @param p_extension_funcs A pointer to a GDExtensionClassCreationInfo2 struct.
+ */
+typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClass3)(GDExtensionClassLibraryPtr p_library, GDExtensionConstStringNamePtr p_class_name, GDExtensionConstStringNamePtr p_parent_class_name, const GDExtensionClassCreationInfo3 *p_extension_funcs);
+
 /**
  * @name classdb_register_extension_class_method
  * @since 4.1
diff --git a/include/godot_cpp/core/class_db.hpp b/include/godot_cpp/core/class_db.hpp
index e5bccf3d4..91748e65c 100644
--- a/include/godot_cpp/core/class_db.hpp
+++ b/include/godot_cpp/core/class_db.hpp
@@ -110,7 +110,7 @@ class ClassDB {
 	static void bind_method_godot(const StringName &p_class_name, MethodBind *p_method);
 
 	template <class T, bool is_abstract>
-	static void _register_class(bool p_virtual = false, bool p_exposed = true);
+	static void _register_class(bool p_virtual = false, bool p_exposed = true, bool p_runtime = false);
 
 	template <class T>
 	static GDExtensionObjectPtr _create_instance_func(void *data) {
@@ -146,6 +146,8 @@ class ClassDB {
 	static void register_abstract_class();
 	template <class T>
 	static void register_internal_class();
+	template <class T>
+	static void register_runtime_class();
 
 	_FORCE_INLINE_ static void _register_engine_class(const StringName &p_name, const GDExtensionInstanceBindingCallbacks *p_callbacks) {
 		instance_binding_callbacks[p_name] = p_callbacks;
@@ -199,7 +201,7 @@ class ClassDB {
 	}
 
 template <class T, bool is_abstract>
-void ClassDB::_register_class(bool p_virtual, bool p_exposed) {
+void ClassDB::_register_class(bool p_virtual, bool p_exposed, bool p_runtime) {
 	static_assert(TypesAreSame<typename T::self_type, T>::value, "Class not declared properly, please use GDCLASS.");
 	instance_binding_callbacks[T::get_class_static()] = &T::_gde_binding_callbacks;
 
@@ -217,10 +219,11 @@ void ClassDB::_register_class(bool p_virtual, bool p_exposed) {
 	class_register_order.push_back(cl.name);
 
 	// Register this class with Godot
-	GDExtensionClassCreationInfo2 class_info = {
+	GDExtensionClassCreationInfo3 class_info = {
 		p_virtual, // GDExtensionBool is_virtual;
 		is_abstract, // GDExtensionBool is_abstract;
 		p_exposed, // GDExtensionBool is_exposed;
+		p_runtime, // GDExtensionBool is_runtime;
 		T::set_bind, // GDExtensionClassSet set_func;
 		T::get_bind, // GDExtensionClassGet get_func;
 		T::has_get_property_list() ? T::get_property_list_bind : nullptr, // GDExtensionClassGetPropertyList get_property_list_func;
@@ -242,7 +245,7 @@ void ClassDB::_register_class(bool p_virtual, bool p_exposed) {
 		(void *)&T::get_class_static(), // void *class_userdata;
 	};
 
-	internal::gdextension_interface_classdb_register_extension_class2(internal::library, cl.name._native_ptr(), cl.parent_name._native_ptr(), &class_info);
+	internal::gdextension_interface_classdb_register_extension_class3(internal::library, cl.name._native_ptr(), cl.parent_name._native_ptr(), &class_info);
 
 	// call bind_methods etc. to register all members of the class
 	T::initialize_class();
@@ -266,6 +269,11 @@ void ClassDB::register_internal_class() {
 	ClassDB::_register_class<T, false>(false, false);
 }
 
+template <class T>
+void ClassDB::register_runtime_class() {
+	ClassDB::_register_class<T, false>(false, true, true);
+}
+
 template <class N, class M, typename... VarArgs>
 MethodBind *ClassDB::bind_method(N p_method_name, M p_method, VarArgs... p_args) {
 	Variant args[sizeof...(p_args) + 1] = { p_args..., Variant() }; // +1 makes sure zero sized arrays are also supported.
@@ -325,6 +333,7 @@ MethodBind *ClassDB::bind_vararg_method(uint32_t p_flags, StringName p_name, M p
 #define GDREGISTER_VIRTUAL_CLASS(m_class) ClassDB::register_class<m_class>(true);
 #define GDREGISTER_ABSTRACT_CLASS(m_class) ClassDB::register_abstract_class<m_class>();
 #define GDREGISTER_INTERNAL_CLASS(m_class) ClassDB::register_internal_class<m_class>();
+#define GDREGISTER_RUNTIME_CLASS(m_class) ClassDB::register_runtime_class<m_class>();
 
 } // namespace godot
 
diff --git a/include/godot_cpp/godot.hpp b/include/godot_cpp/godot.hpp
index 1b420d38e..c4e5d8385 100644
--- a/include/godot_cpp/godot.hpp
+++ b/include/godot_cpp/godot.hpp
@@ -177,7 +177,7 @@ extern "C" GDExtensionInterfacePlaceHolderScriptInstanceUpdate gdextension_inter
 extern "C" GDExtensionInterfaceClassdbConstructObject gdextension_interface_classdb_construct_object;
 extern "C" GDExtensionInterfaceClassdbGetMethodBind gdextension_interface_classdb_get_method_bind;
 extern "C" GDExtensionInterfaceClassdbGetClassTag gdextension_interface_classdb_get_class_tag;
-extern "C" GDExtensionInterfaceClassdbRegisterExtensionClass2 gdextension_interface_classdb_register_extension_class2;
+extern "C" GDExtensionInterfaceClassdbRegisterExtensionClass3 gdextension_interface_classdb_register_extension_class3;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassMethod gdextension_interface_classdb_register_extension_class_method;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassVirtualMethod gdextension_interface_classdb_register_extension_class_virtual_method;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassIntegerConstant gdextension_interface_classdb_register_extension_class_integer_constant;
diff --git a/src/godot.cpp b/src/godot.cpp
index a80ad90da..dd8ace3c8 100644
--- a/src/godot.cpp
+++ b/src/godot.cpp
@@ -183,7 +183,7 @@ GDExtensionInterfacePlaceHolderScriptInstanceUpdate gdextension_interface_placeh
 GDExtensionInterfaceClassdbConstructObject gdextension_interface_classdb_construct_object = nullptr;
 GDExtensionInterfaceClassdbGetMethodBind gdextension_interface_classdb_get_method_bind = nullptr;
 GDExtensionInterfaceClassdbGetClassTag gdextension_interface_classdb_get_class_tag = nullptr;
-GDExtensionInterfaceClassdbRegisterExtensionClass2 gdextension_interface_classdb_register_extension_class2 = nullptr;
+GDExtensionInterfaceClassdbRegisterExtensionClass3 gdextension_interface_classdb_register_extension_class3 = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassMethod gdextension_interface_classdb_register_extension_class_method = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassVirtualMethod gdextension_interface_classdb_register_extension_class_virtual_method = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassIntegerConstant gdextension_interface_classdb_register_extension_class_integer_constant = nullptr;
@@ -423,7 +423,7 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	LOAD_PROC_ADDRESS(classdb_construct_object, GDExtensionInterfaceClassdbConstructObject);
 	LOAD_PROC_ADDRESS(classdb_get_method_bind, GDExtensionInterfaceClassdbGetMethodBind);
 	LOAD_PROC_ADDRESS(classdb_get_class_tag, GDExtensionInterfaceClassdbGetClassTag);
-	LOAD_PROC_ADDRESS(classdb_register_extension_class2, GDExtensionInterfaceClassdbRegisterExtensionClass2);
+	LOAD_PROC_ADDRESS(classdb_register_extension_class3, GDExtensionInterfaceClassdbRegisterExtensionClass3);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_method, GDExtensionInterfaceClassdbRegisterExtensionClassMethod);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_virtual_method, GDExtensionInterfaceClassdbRegisterExtensionClassVirtualMethod);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_integer_constant, GDExtensionInterfaceClassdbRegisterExtensionClassIntegerConstant);
diff --git a/test/src/example.cpp b/test/src/example.cpp
index 53d11f4a7..136ac94c3 100644
--- a/test/src/example.cpp
+++ b/test/src/example.cpp
@@ -637,3 +637,23 @@ String Example::test_virtual_implemented_in_script(const String &p_name, int p_v
 	}
 	return "Unimplemented";
 }
+
+void ExampleRuntime::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_prop_value", "value"), &ExampleRuntime::set_prop_value);
+	ClassDB::bind_method(D_METHOD("get_prop_value"), &ExampleRuntime::get_prop_value);
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "prop_value"), "set_prop_value", "get_prop_value");
+}
+
+void ExampleRuntime::set_prop_value(int p_prop_value) {
+	prop_value = p_prop_value;
+}
+
+int ExampleRuntime::get_prop_value() const {
+	return prop_value;
+}
+
+ExampleRuntime::ExampleRuntime() {
+}
+
+ExampleRuntime::~ExampleRuntime() {
+}
diff --git a/test/src/example.h b/test/src/example.h
index 1c577203b..7da7b08a2 100644
--- a/test/src/example.h
+++ b/test/src/example.h
@@ -220,4 +220,20 @@ class ExampleConcrete : public ExampleAbstractBase {
 	virtual int test_function() override { return 25; }
 };
 
+class ExampleRuntime : public Node {
+	GDCLASS(ExampleRuntime, Node);
+
+	int prop_value = 12;
+
+protected:
+	static void _bind_methods();
+
+public:
+	void set_prop_value(int p_prop_value);
+	int get_prop_value() const;
+
+	ExampleRuntime();
+	~ExampleRuntime();
+};
+
 #endif // EXAMPLE_CLASS_H
diff --git a/test/src/register_types.cpp b/test/src/register_types.cpp
index 58080d209..5c38241f8 100644
--- a/test/src/register_types.cpp
+++ b/test/src/register_types.cpp
@@ -27,6 +27,7 @@ void initialize_example_module(ModuleInitializationLevel p_level) {
 	ClassDB::register_class<ExampleVirtual>(true);
 	ClassDB::register_abstract_class<ExampleAbstractBase>();
 	ClassDB::register_class<ExampleConcrete>();
+	ClassDB::register_runtime_class<ExampleRuntime>();
 }
 
 void uninitialize_example_module(ModuleInitializationLevel p_level) {
