diff --git a/CHANGELOG.md b/CHANGELOG.md
index 32b1c2d..0bb8a39 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,11 +9,25 @@ Version numbers follow [Semantic Versioning](https://semver.org/spec/v2.0.0.html
 
 ## [Unreleased]
 
+---
+
+## [0.3.2] — 2026-08-12
+
 ### Removed
 - `nc3.lu.svg`, a saved scan report accidentally committed with v0.3.1.
   Top-level `.svg`/`.html`/`.txt` report outputs are now git-ignored to
   prevent a recurrence.
 
+### Changed
+- `pyproject.toml`: `license` is now the canonical SPDX expression
+  `GPL-3.0-only` instead of the deprecated `GPL-3.0` identifier. The license
+  itself is unchanged — only its machine-readable spelling.
+- `pyproject.toml`: the build requirement is now `setuptools>=77`, the first
+  release implementing PEP 639 (a string `license` holding an SPDX expression,
+  plus `license-files`). The previous `setuptools>=68` allowed versions that
+  reject a string `license` value, so a build in a clean environment could
+  resolve a setuptools too old to understand this metadata.
+
 ---
 
 ## [0.3.1] — 2026-07-15
@@ -296,7 +310,8 @@ Version numbers follow [Semantic Versioning](https://semver.org/spec/v2.0.0.html
 
 ---
 
-[Unreleased]: https://github.com/NC3-TestingPlatform/headersvalidator/compare/v0.3.1...HEAD
+[Unreleased]: https://github.com/NC3-TestingPlatform/headersvalidator/compare/v0.3.2...HEAD
+[0.3.2]: https://github.com/NC3-TestingPlatform/headersvalidator/compare/v0.3.1...v0.3.2
 [0.3.1]: https://github.com/NC3-TestingPlatform/headersvalidator/compare/v0.3.0...v0.3.1
 [0.3.0]: https://github.com/NC3-TestingPlatform/headersvalidator/compare/v0.2.3...v0.3.0
 [0.2.3]: https://github.com/NC3-TestingPlatform/headersvalidator/compare/v0.2.2...v0.2.3
diff --git a/headersvalidator/__init__.py b/headersvalidator/__init__.py
index d803426..2368b37 100644
--- a/headersvalidator/__init__.py
+++ b/headersvalidator/__init__.py
@@ -5,7 +5,7 @@
 try:
     __version__ = version("headersvalidator")
 except PackageNotFoundError:  # pragma: no cover – only when package not installed
-    __version__ = "0.3.1"
+    __version__ = "0.3.2"
 
 # NullHandler so library users who have not configured logging
 # do not see "No handler found" warnings (PEP 3118 / logging HOWTO).
diff --git a/pyproject.toml b/pyproject.toml
index d83b72c..5eaef41 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,14 +1,14 @@
 [build-system]
-requires = ["setuptools>=68", "wheel"]
+requires = ["setuptools>=77", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [project]
 name = "headersvalidator"
-version = "0.3.1"
+version = "0.3.2"
 description = "HTTP response header validator — RFC 9110, RFC 9111, OWASP, IANA"
 readme = "README.md"
 requires-python = ">=3.11"
-license = "GPL-3.0"
+license = "GPL-3.0-only"
 license-files = ["LICENSE"]
 authors = [{ name = "t0kubetsu" }]
 keywords = [