diff --git a/CHANGELOG.md b/CHANGELOG.md
index 621195b6..116d00bf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,12 +17,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
-- Use `py::type::handle_of(obj)` rather than deprecated `obj.get_type()` by [@XuehaiPan](https://github.com/XuehaiPan) in [#49](https://github.com/metaopt/optree/pull/49).
-- Bump `abseil-cpp` version to 20230125.3 by [@XuehaiPan](https://github.com/XuehaiPan) in [#57](https://github.com/metaopt/optree/pull/57).
+-
+-
 
 ### Fixed
 
-- Add `@runtime_checkable` decorator for `CustomTreeNode` protocol class by [@XuehaiPan](https://github.com/XuehaiPan) in [#56](https://github.com/metaopt/optree/pull/56).
+-
 
 ### Removed
 
@@ -30,6 +30,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ------
 
+## [0.9.1] - 2023-05-23
+
+### Changed
+
+- Use `py::type::handle_of(obj)` rather than deprecated `obj.get_type()` by [@XuehaiPan](https://github.com/XuehaiPan) in [#49](https://github.com/metaopt/optree/pull/49).
+- Bump `abseil-cpp` version to 20230125.3 by [@XuehaiPan](https://github.com/XuehaiPan) in [#57](https://github.com/metaopt/optree/pull/57).
+
+### Fixed
+
+- Add `@runtime_checkable` decorator for `CustomTreeNode` protocol class by [@XuehaiPan](https://github.com/XuehaiPan) in [#56](https://github.com/metaopt/optree/pull/56).
+
+------
+
 ## [0.9.0] - 2023-03-23
 
 ### Added
@@ -198,7 +211,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ------
 
-[Unreleased]: https://github.com/metaopt/optree/compare/v0.9.0...HEAD
+[Unreleased]: https://github.com/metaopt/optree/compare/v0.9.1...HEAD
+[0.9.1]: https://github.com/metaopt/optree/compare/v0.9.0...v0.9.1
 [0.9.0]: https://github.com/metaopt/optree/compare/v0.8.0...v0.9.0
 [0.8.0]: https://github.com/metaopt/optree/compare/v0.7.0...v0.8.0
 [0.7.0]: https://github.com/metaopt/optree/compare/v0.6.0...v0.7.0
diff --git a/optree/version.py b/optree/version.py
index ba3e072f..3917ecc3 100644
--- a/optree/version.py
+++ b/optree/version.py
@@ -14,7 +14,7 @@
 # ==============================================================================
 """OpTree: Optimized PyTree Utilities."""
 
-__version__ = '0.9.0'
+__version__ = '0.9.1'
 __license__ = 'Apache License, Version 2.0'
 __author__ = 'OpTree Contributors'
 __release__ = False