diff --git a/CHANGELOG.md b/CHANGELOG.md
index 969f5c17..10c5f766 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,5 @@
+# [9.0.0-next.0](https://github.com/vivliostyle/vivliostyle-cli/compare/v8.17.1...v9.0.0-next.0) (2025-01-06)
+
 ## [8.17.1](https://github.com/vivliostyle/vivliostyle-cli/compare/v8.17.0...v8.17.1) (2024-11-27)
 
 ### Bug Fixes
diff --git a/package.json b/package.json
index 8845c469..eed455c9 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@vivliostyle/cli",
   "description": "Save the pdf file via headless browser and Vivliostyle.",
-  "version": "8.17.1",
+  "version": "9.0.0-next.0",
   "author": "spring_raining <harusamex.com@gmail.com>",
   "type": "module",
   "scripts": {