diff --git a/CHANGELOG.md b/CHANGELOG.md
index a3a72ff..1a9289d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Change Log
 
+<h2><a href="https://github.com/terrakuh/curlio/compare/v0.3.3..v0.4">v0.4</a> - 2022-11-27</h2>
+
+### Changed
+- Implementation
+
 <h2><a href="https://github.com/terrakuh/curlio/compare/v0.3.2..v0.3.3">v0.3.3</a> - 2022-06-10</h2>
 
 ### Added
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 62c533b..3e5cac4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.16)
 
 project(
   curlio
-  VERSION 0.3.3
+  VERSION 0.4.0
   DESCRIPTION "The simple glue for cURL and Boost.ASIO"
   HOMEPAGE_URL "https://github.com/terrakuh/curlio"
   LANGUAGES CXX
diff --git a/README.md b/README.md
index b02aae8..fba2c93 100644
--- a/README.md
+++ b/README.md
@@ -15,8 +15,8 @@ auto session = curlio::make_session<boost::asio::any_io_executor>(service.get_ex
 
 // Create request and set options.
 auto request = curlio::make_request(session);
-curl_easy_setopt(request->native_handle(), CURLOPT_URL, "http://example.com");
-curl_easy_setopt(request->native_handle(), CURLOPT_USERAGENT, "cURLio");
+request->set_option<CURLOPT_URL>("http://example.com");
+request->set_option<CURLOPT_USERAGENT>("cURLio");
 
 // Launches the request which will then run in the background.
 auto response = co_await session->async_start(request, asio::use_awaitable);
@@ -52,7 +52,7 @@ cmake --install curlio/build
 And then in your `CMakeLists.txt`:
 
 ```cmake
-find_package(curlio 0.3.3 REQUIRED)
+find_package(curlio 0.4 REQUIRED)
 target_link_libraries(my-target PRIVATE curlio::curlio)
 ```