diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 31bfa26..6454bd3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -29,5 +29,7 @@ jobs:
       pull-requests: write
     uses: fastify/workflows/.github/workflows/plugins-ci.yml@ef591e2186785d5ab36b9fe6a79c7ce2f1d94e57 # v7.0.0
     with:
+      node-versions: '["22", "24", "26"]'
       license-check: true
       lint: true
+
diff --git a/README.md b/README.md
index 6e3f0a1..1278556 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,44 @@ npm i @fastify/flash
 
 Flash messages are stored in the session. First, we need to register the session plugin: [@fastify/secure-session](https://www.npmjs.com/package/@fastify/secure-session).
 
+### ESM
+
+```javascript
+import { readFileSync } from 'node:fs'
+import { join } from 'node:path'
+import Fastify from 'fastify'
+import fastifySession from '@fastify/secure-session'
+import fastifyFlash from '@fastify/flash'
+
+const fastify = Fastify()
+
+fastify.register(fastifySession, {
+  // adapt this to point to the directory where secret-key is located
+  key: readFileSync(join(import.meta.dirname, 'secret-key')),
+  cookie: {
+    // options from setCookie, see https://github.com/fastify/fastify-cookie
+    path: "/"
+  }
+})
+fastify.register(fastifyFlash, {
+  prefix: "/"
+})
+
+fastify.get('/test', (req, reply) => {
+  req.flash('warning', ['username required', 'password required'])
+
+  const warning = reply.flash('warning')
+  reply.send({ warning }) // {"warning":["username required","password required"]}
+})
+```
+
+### CommonJS
+
+Even though this package ships as ESM, it can still be `require()`'d from a CommonJS project (see the [Install](#install) note above):
+
 ```javascript
+const fs = require('node:fs')
+const path = require('node:path')
 const fastify = require('fastify')()
 const fastifySession = require('@fastify/secure-session')
 const fastifyFlash = require('@fastify/flash')
diff --git a/eslint.config.js b/eslint.config.cjs
similarity index 100%
rename from eslint.config.js
rename to eslint.config.cjs
diff --git a/package.json b/package.json
index 6061398..c589a67 100644
--- a/package.json
+++ b/package.json
@@ -2,8 +2,15 @@
   "name": "@fastify/flash",
   "version": "6.0.5",
   "description": "Flash message plugin for fastify.",
-  "main": "./lib",
-  "type": "commonjs",
+  "type": "module",
+  "main": "./lib/index.js",
+  "types": "./lib/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/index.d.ts",
+      "default": "./lib/index.js"
+    }
+  },
   "scripts": {
     "build": "npm run clean-build && npm run lint && tsc -p ./tsconfig.build.json",
     "clean-build": "rimraf ./lib && mkdir lib",
@@ -57,7 +64,7 @@
   "devDependencies": {
     "@fastify/secure-session": "^8.0.0",
     "@types/node": "^26.0.0",
-    "borp": "^0.21.0",
+    "borp": "^1.0.0",
     "eslint": "^9.35.0",
     "fastify": "^5.0.0",
     "neostandard": "^0.13.0",
@@ -72,5 +79,8 @@
   ],
   "publishConfig": {
     "access": "public"
+  },
+  "engines": {
+    "node": ">=20.19.0 <21 || >=22.12.0"
   }
 }
diff --git a/src/index.ts b/src/index.ts
index 9d5ddf8..c936e15 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,5 +1,5 @@
-import fp = require('fastify-plugin')
-import { flashFactory } from './flash'
+import fp from 'fastify-plugin'
+import { flashFactory } from './flash.ts'
 
 declare module 'fastify' {
   export interface FastifyRequest {
@@ -10,10 +10,9 @@ declare module 'fastify' {
   }
 }
 
-export = fp<{ core?: string }>(
+export default fp<{ core?: string }>(
   function (fastify, _opts, done) {
     const flash = flashFactory()
-
     fastify.decorateRequest('flash', flash.request)
     fastify.decorateReply('flash', flash.reply)
     done()
diff --git a/test/index.test.ts b/test/index.test.ts
index d3c8766..6994191 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -1,12 +1,12 @@
-import { test, TestContext } from 'node:test'
+import { test, type TestContext } from 'node:test'
 import { join } from 'node:path'
 import { readFileSync } from 'node:fs'
 import Fastify from 'fastify'
-import fastifySession, { Session, SessionData } from '@fastify/secure-session'
+import fastifySession, { type Session, type SessionData } from '@fastify/secure-session'
 import querystring from 'node:querystring'
-import fastifyFlash from '../src'
+import fastifyFlash from '../src/index.ts'
 
-const key = readFileSync(join(__dirname, '..', '..', 'secret-key'))
+const key = readFileSync(join(import.meta.dirname, '..', 'secret-key'))
 
 test('should set error message and and clear up after displaying.', async (t: TestContext) => {
   t.plan(5)
diff --git a/tsconfig.json b/tsconfig.json
index ed79f80..fde3b51 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,9 +1,13 @@
 {
   "compilerOptions": {
-    "moduleResolution": "node16",
+    "target": "esnext",
+    "module": "nodenext",
+    "moduleResolution": "nodenext",
+    "allowImportingTsExtensions": true,
+    "rewriteRelativeImportExtensions": true,
+    "verbatimModuleSyntax": true,
+    "erasableSyntaxOnly": true,
     "declaration": true,
-    "target": "es2022",
-    "module": "node16",
     "outDir": "lib",
     "pretty": true,
     "noEmitOnError": true,