diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,15 @@
 ## [Unreleased]
 
 
+## [0.3.1.0] — 2026-07-23
+
+### Changed
+
+- Co-released with `keiki-0.3.1.0` and `keiki-codec-json-0.3.1.0`; existing
+  `^>=0.3` bounds admit the additive shape API while retaining the current PVP
+  major range.
+
+
 ## [0.3.0.0] — 2026-07-23
 
 ### Changed
diff --git a/keiki-codec-json-test.cabal b/keiki-codec-json-test.cabal
--- a/keiki-codec-json-test.cabal
+++ b/keiki-codec-json-test.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               keiki-codec-json-test
-version:            0.3.0.0
+version:            0.3.1.0
 synopsis:
   Property-test toolkit for keiki-codec-json downstream consumers.