Bump version to 2.3.1

Change-Id: I858cc6b31e9cbcab88f4cff080e19e8b861ec6cb
diff --git a/CHANGELOG.md b/CHANGELOG.md
index faa935c..93e3e77 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,9 +1,11 @@
 # Changelog
 
 
-## 2.3.1-SNAPSHOT
+## 2.3.1 [2026-01-28]
 
 * Fixed soft hyphens (U+00AD) being incorrectly treated as token boundaries (issue #131)
+* Updated dependencies
+* Improved compatibility with Java 25 (fixed deprecation warnings)
 
 ## 2.3.0 [2025-12-23]
 
diff --git a/pom.xml b/pom.xml
index 85369ff..dd28bf4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
 
     <groupId>de.ids-mannheim.korap.tokenizer</groupId>
     <artifactId>KorAP-Tokenizer</artifactId>
-    <version>2.3.1-SNAPSHOT</version>
+    <version>2.3.1</version>
 
     <name>KorAP-Tokenizer</name>
     <description>DFA tokenizer with character offset output, large abbreviation tables and CMC support.</description>