diff --git a/test/test_fast_api.cpp b/test/test_fast_api.cpp
index 02e7ad7..66e2266 100644
--- a/test/test_fast_api.cpp
+++ b/test/test_fast_api.cpp
@@ -158,6 +158,28 @@ void test_fast_api()
 			run_script<int>(context, "p.fast_xy = 77; p.x"), 77);
 	}
 
+	// --- Class property with fast getter + slow setter ---
+	{
+		struct Gauge
+		{
+			int32_t val = 0;
+			int32_t get_val() const { return val; }
+			void set_val(v8::Isolate*, int32_t v) { val = v; }
+		};
+
+		v8pp::class_<Gauge> gauge_class(isolate);
+		gauge_class
+			.ctor<>()
+			.property("mixed", v8pp::fast_fn<&Gauge::get_val>, &Gauge::set_val);
+		context.class_("Gauge", gauge_class);
+
+		check_eq("fast_api: mixed property get",
+			run_script<int>(context, "var g = new Gauge(); g.mixed"), 0);
+
+		check_eq("fast_api: mixed property set+get",
+			run_script<int>(context, "g.mixed = 42; g.mixed"), 42);
+	}
+
 	// --- Module property with fast API ---
 	{
 		static int32_t mod_value = 0;
@@ -188,4 +210,24 @@ void test_fast_api()
 		check_eq("fast_api: module read-only property is readonly",
 			run_script<int>(context, "fmod.fast_const = 999; fmod.fast_const"), 123);
 	}
+
+	// --- Module property with fast getter + slow setter ---
+	{
+		static int32_t mixed_val = 0;
+
+		struct MixedMod
+		{
+			static int32_t get_val() { return mixed_val; }
+			static void set_val(int32_t v) { mixed_val = v; }
+		};
+
+		v8pp::module m(isolate);
+		m.property("mixed", v8pp::fast_fn<&MixedMod::get_val>, &MixedMod::set_val);
+		context.module("mmod", m);
+
+		mixed_val = 0;
+		check_eq("fast_api: module mixed property set+get",
+			run_script<int>(context, "mmod.mixed = 33; mmod.mixed"), 33);
+		check_eq("fast_api: module mixed property updated C++ side", mixed_val, 33);
+	}
 }
diff --git a/v8pp/CMakeLists.txt b/v8pp/CMakeLists.txt
index f8ea84a..fb454b6 100644
--- a/v8pp/CMakeLists.txt
+++ b/v8pp/CMakeLists.txt
@@ -60,6 +60,7 @@ set(V8PP_HEADERS
 	promise.hpp
 	property.hpp
 	ptr_traits.hpp
+	string_utils.hpp
 	throw_ex.hpp
 	type_info.hpp
 	utility.hpp
@@ -71,6 +72,7 @@ if(V8PP_HEADER_ONLY)
 		class.ipp
 		context_store.ipp
 		json.ipp
+		string_utils.ipp
 		throw_ex.ipp
 		version.ipp
 	)
@@ -81,6 +83,7 @@ else()
 		context.cpp
 		context_store.cpp
 		convert.cpp
+		string_utils.cpp
 		json.cpp
 		throw_ex.cpp
 		version.cpp
diff --git a/v8pp/class.hpp b/v8pp/class.hpp
index 341b5e0..10f079b 100644
--- a/v8pp/class.hpp
+++ b/v8pp/class.hpp
@@ -741,6 +741,34 @@ class class_
 		return *this;
 	}
 
+	/// Set read/write class property with V8 Fast API getter and slow setter
+	template<auto GetPtr, typename SetFunction>
+	requires(!is_fast_function<std::decay_t<SetFunction>>::value)
+	class_& property(std::string_view name, fast_function<GetPtr>, SetFunction&& set)
+	{
+		using Setter = std::decay_t<SetFunction>;
+		static_assert(std::is_member_function_pointer_v<SetFunction> || detail::is_callable<Setter>::value, "SetFunction must be callable");
+
+		v8::HandleScope scope(isolate());
+
+		v8::Local<v8::Name> v8_name = v8pp::to_v8_name(isolate(), name);
+		auto getter_template = wrap_function_template<GetPtr, Traits>(
+			isolate(), fast_function<GetPtr>{},
+			v8::SideEffectType::kHasNoSideEffect);
+		auto setter_template = v8::FunctionTemplate::New(isolate(),
+			&detail::forward_function<Traits, Setter>,
+			detail::external_data::set(isolate(), Setter(std::forward<SetFunction>(set))),
+			v8::Local<v8::Signature>(), 0,
+			v8::ConstructorBehavior::kThrow,
+			v8::SideEffectType::kHasSideEffectToReceiver);
+
+		class_info_.js_function_template()->PrototypeTemplate()->SetAccessorProperty(
+			v8_name, getter_template, setter_template,
+			v8::PropertyAttribute(v8::DontDelete));
+
+		return *this;
+	}
+
 	/// Set read/write class property with V8 Fast API getter and setter
 	template<auto GetPtr, auto SetPtr>
 	class_& property(std::string_view name, fast_function<GetPtr>, fast_function<SetPtr>)
diff --git a/v8pp/convert.hpp b/v8pp/convert.hpp
index be7a437..b604b96 100644
--- a/v8pp/convert.hpp
+++ b/v8pp/convert.hpp
@@ -25,6 +25,7 @@
 #include <optional>
 
 #include "v8pp/ptr_traits.hpp"
+#include "v8pp/string_utils.hpp"
 #include "v8pp/utility.hpp"
 
 namespace v8pp {
@@ -1093,10 +1094,7 @@ struct convert<std::filesystem::path, void>
 	{
 		std::string str = convert<std::string>::from_v8(isolate, value);
 #ifdef WIN32
-		int sz = MultiByteToWideChar(CP_UTF8, 0, str.data(), static_cast<int>(str.size()), nullptr, 0);
-		std::wstring w(sz, 0);
-		MultiByteToWideChar(CP_UTF8, 0, str.data(), static_cast<int>(str.size()), w.data(), sz);
-		return std::filesystem::path(w);
+		return std::filesystem::path(utf8_to_wide(str));
 #else
 		return std::filesystem::path(str);
 #endif
@@ -1106,14 +1104,10 @@ struct convert<std::filesystem::path, void>
 	{
 		if (auto str = convert<std::string>::try_from_v8(isolate, value))
 		{
-			std::string s = *std::move(str);
 #ifdef WIN32
-			int sz = MultiByteToWideChar(CP_UTF8, 0, s.data(), static_cast<int>(s.size()), nullptr, 0);
-			std::wstring w(sz, 0);
-			MultiByteToWideChar(CP_UTF8, 0, s.data(), static_cast<int>(s.size()), w.data(), sz);
-			return std::filesystem::path(w);
+			return std::filesystem::path(utf8_to_wide(*std::move(str)));
 #else
-			return std::filesystem::path(s);
+			return std::filesystem::path(*std::move(str));
 #endif
 		}
 		return std::nullopt;
@@ -1122,11 +1116,7 @@ struct convert<std::filesystem::path, void>
 	static to_type to_v8(v8::Isolate* isolate, from_type const& value)
 	{
 #ifdef WIN32
-		std::wstring w = value.generic_wstring();
-		int sz = WideCharToMultiByte(CP_UTF8, 0, w.data(), static_cast<int>(w.size()), nullptr, 0, nullptr, nullptr);
-		std::string utf8(sz, 0);
-		WideCharToMultiByte(CP_UTF8, 0, w.data(), static_cast<int>(w.size()), utf8.data(), sz, nullptr, nullptr);
-		return convert<std::string>::to_v8(isolate, utf8);
+		return convert<std::string>::to_v8(isolate, wide_to_utf8(value.generic_wstring()));
 #else
 		return convert<std::string>::to_v8(isolate, value.string());
 #endif
diff --git a/v8pp/module.hpp b/v8pp/module.hpp
index e8cdeda..6b94e59 100644
--- a/v8pp/module.hpp
+++ b/v8pp/module.hpp
@@ -178,6 +178,33 @@ class module
 		return *this;
 	}
 
+	/// Set read/write module property with V8 Fast API getter and slow setter
+	template<auto GetPtr, typename SetFunction>
+	requires(!is_fast_function<std::decay_t<SetFunction>>::value)
+	module& property(char const* name, fast_function<GetPtr>, SetFunction&& set)
+	{
+		using Setter = std::decay_t<SetFunction>;
+		static_assert(detail::is_callable<Setter>::value, "SetFunction must be callable");
+
+		v8::HandleScope scope(isolate_);
+
+		v8::Local<v8::Name> v8_name = v8pp::to_v8_name(isolate_, name);
+		auto getter_template = wrap_function_template<GetPtr>(
+			isolate_, fast_function<GetPtr>{},
+			v8::SideEffectType::kHasNoSideEffect);
+		auto setter_template = v8::FunctionTemplate::New(isolate_,
+			&detail::forward_function<raw_ptr_traits, Setter>,
+			detail::external_data::set(isolate_, Setter(std::forward<SetFunction>(set))),
+			v8::Local<v8::Signature>(), 0,
+			v8::ConstructorBehavior::kThrow,
+			v8::SideEffectType::kHasSideEffectToReceiver);
+
+		obj_->SetAccessorProperty(v8_name, getter_template, setter_template,
+			v8::PropertyAttribute(v8::DontDelete));
+
+		return *this;
+	}
+
 	/// Set read/write module property with V8 Fast API getter and setter
 	template<auto GetPtr, auto SetPtr>
 	module& property(char const* name, fast_function<GetPtr>, fast_function<SetPtr>)
diff --git a/v8pp/string_utils.cpp b/v8pp/string_utils.cpp
new file mode 100644
index 0000000..27c38bb
--- /dev/null
+++ b/v8pp/string_utils.cpp
@@ -0,0 +1,5 @@
+#include "v8pp/config.hpp"
+
+#if !V8PP_HEADER_ONLY
+#include "v8pp/string_utils.ipp"
+#endif
diff --git a/v8pp/string_utils.hpp b/v8pp/string_utils.hpp
new file mode 100644
index 0000000..aca7558
--- /dev/null
+++ b/v8pp/string_utils.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <string>
+#include <string_view>
+
+#include "v8pp/config.hpp"
+
+namespace v8pp {
+
+#ifdef WIN32
+std::wstring utf8_to_wide(std::string_view utf8);
+std::string wide_to_utf8(std::wstring_view wide);
+#endif
+
+} // namespace v8pp
+
+#if V8PP_HEADER_ONLY
+#include "v8pp/string_utils.ipp"
+#endif
diff --git a/v8pp/string_utils.ipp b/v8pp/string_utils.ipp
new file mode 100644
index 0000000..eb22da8
--- /dev/null
+++ b/v8pp/string_utils.ipp
@@ -0,0 +1,33 @@
+#include "v8pp/string_utils.hpp"
+
+#ifdef WIN32
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+#include <windows.h>
+#endif
+
+namespace v8pp {
+
+#ifdef WIN32
+V8PP_IMPL std::wstring utf8_to_wide(std::string_view utf8)
+{
+	int sz = MultiByteToWideChar(CP_UTF8, 0, utf8.data(), static_cast<int>(utf8.size()), nullptr, 0);
+	std::wstring w(sz, 0);
+	MultiByteToWideChar(CP_UTF8, 0, utf8.data(), static_cast<int>(utf8.size()), w.data(), sz);
+	return w;
+}
+
+V8PP_IMPL std::string wide_to_utf8(std::wstring_view wide)
+{
+	int sz = WideCharToMultiByte(CP_UTF8, 0, wide.data(), static_cast<int>(wide.size()), nullptr, 0, nullptr, nullptr);
+	std::string utf8(sz, 0);
+	WideCharToMultiByte(CP_UTF8, 0, wide.data(), static_cast<int>(wide.size()), utf8.data(), sz, nullptr, nullptr);
+	return utf8;
+}
+#endif
+
+} // namespace v8pp