diff --git a/CHANGELOG.md b/CHANGELOG.md
index d39cf88..a5bc4d8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ e il progetto aderisce al [Semantic Versioning](https://semver.org/spec/v2.0.0.h
 
 ## [Unreleased]
 
+## [2.3.1] — 2026-05-03
+
+### Fixed
+- f-string syntax error in all `tools/legacy/` build scripts: nested double-quoted expressions (`{"="*60}`) are only valid in Python 3.12+; replaced with single-quoted equivalents (`{'='*60}`) for compatibility with Python 3.10/3.11 used on CI
+
 ## [2.3.0] — 2026-05-03
 
 ### Added
diff --git a/VERSION b/VERSION
index 276cbf9..2bf1c1c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.0
+2.3.1