diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1add7dd..777567d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,21 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
+# [1.2.1] 2025-11-03
+
+
+### Added
+
+- Jupyter notebook for Authentication, EWSS
+
+### Fixed
+
+- Build issue on Windows (removed pysolid)
+
+### Changed
+
+- Updated RTCM SC134 messages
+
 # [1.2.0] 2025-10-14
 
 ### Added
diff --git a/pyproject.toml b/pyproject.toml
index 24ac1db..75dccdd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "cssrlib"
-version = "1.2.0"
+version = "1.2.1"
 description = "Python Toolkit for PPP/PPP-RTK positioning"
 authors = [
     {name="Rui Hirokawa", email="rui.hirokawa@gmail.com"},
diff --git a/setup.cfg b/setup.cfg
index 14442b8..413f56d 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = cssrlib
-version = 1.2.0
+version = 1.2.1
 author = Rui Hirokawa
 author_email = rui.hirokawa@gmail.com
 description = Python Toolkit for PPP/PPP-RTK positioning