diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8571652..87fd6e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,7 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [Unreleased]
+## [9.0.0] - 2026-10-30
+
+A major version because **the CSV header changed**: four columns were added in the
+middle of it, so a reader that takes columns by position gets the wrong ones
+rather than an error. Read by name. The library API is backward compatible. The
+schema is regenerated from the current spec.
 
 ### Added
 
diff --git a/package-lock.json b/package-lock.json
index 45311b3..6964cfd 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "themeparks",
-  "version": "8.4.0",
+  "version": "9.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "themeparks",
-      "version": "8.4.0",
+      "version": "9.0.0",
       "license": "MIT",
       "bin": {
         "themeparks-backfill": "dist/backfill-cli.js"
diff --git a/package.json b/package.json
index 7c8c1fc..7d19734 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "themeparks",
-  "version": "8.4.0",
+  "version": "9.0.0",
   "description": "Official SDK for the ThemeParks.wiki API",
   "license": "MIT",
   "repository": "github:ThemeParks/ThemeParks_JavaScript",
diff --git a/src/client.ts b/src/client.ts
index 26f76d0..b847176 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -13,7 +13,7 @@ import type { RateLimits } from './ratelimit';
 const DEFAULT_BASE_URL = 'https://api.themeparks.wiki/v1';
 /** Exported so the backfill command can announce the same version rather
  *  than carrying a second literal that drifts. test/unit/version.test.ts pins it. */
-export const PACKAGE_VERSION = '8.4.0';
+export const PACKAGE_VERSION = '9.0.0';
 export const DEFAULT_USER_AGENT = `themeparks-sdk-js/${PACKAGE_VERSION}`;
 
 export interface ThemeParksOptions {