diff --git a/CHANGES.md b/CHANGES.md
index 937300f..864b3d1 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -12,6 +12,12 @@
 
 ## develop
 
+## 2021.3
+
+- [UPDATE] `boost` を `1.76.0` に
+    - @haruyama
+    - https://github.com/shiguredo/cpp-mp4/pull/8
+
 ## 2021.2
 
 - [ADD] av01, av1C box のサポート
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 87ad61c..09ccfb4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,7 +11,7 @@ set(CMAKE_CXX_COMPILER clang++)
 include(cmake/env.cmake)
 include(cmake/tools.cmake)
 
-set_cache_string_from_env(BOOST_VERSION 1.75.0 "Boost のバージョン")
+set_cache_string_from_env(BOOST_VERSION 1.76.0 "Boost のバージョン")
 set_cache_string_from_env(CLI11_VERSION 1.9.1 "CLI11 のバージョン")
 set_cache_string_from_env(FMT_VERSION 7.1.3 "fmt のバージョン")
 set_cache_string_from_env(RAPIDCSV_VERSION 8.48 "rapidcsv のバージョン")
diff --git a/src/version.cpp b/src/version.cpp
index 32b90da..047bc53 100644
--- a/src/version.cpp
+++ b/src/version.cpp
@@ -8,7 +8,7 @@
 namespace shiguredo::mp4 {
 
 std::string get_version_string() {
-  return "2021.2";
+  return "2021.3";
 }
 
 }  // namespace shiguredo::mp4
diff --git a/test/version.cpp b/test/version.cpp
index 0fceb43..1743799 100644
--- a/test/version.cpp
+++ b/test/version.cpp
@@ -7,7 +7,7 @@
 BOOST_AUTO_TEST_SUITE(version)
 
 BOOST_AUTO_TEST_CASE(version_string) {
-  BOOST_REQUIRE_EQUAL("2021.2", shiguredo::mp4::get_version_string());
+  BOOST_REQUIRE_EQUAL("2021.3", shiguredo::mp4::get_version_string());
 }
 
 BOOST_AUTO_TEST_SUITE_END()