diff --git a/eslint.config.mjs b/eslint.config.js
similarity index 100%
rename from eslint.config.mjs
rename to eslint.config.js
diff --git a/jest.config.js b/jest.config.js
index 7cf1c26f..f6a60fb2 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -1,7 +1,9 @@
-module.exports = {
-  preset: 'ts-jest',
+/** @type {import('ts-jest').JestConfigWithTsJest} */
+export default {
+  preset: 'ts-jest/presets/default-esm',
   clearMocks: true,
-  testEnvironment: 'node',
-  testMatch: ['**/*.test.ts'],
-  verbose: true
+  // https://kulshekhar.github.io/ts-jest/docs/guides/esm-support/
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1',
+  },
 }
diff --git a/package.json b/package.json
index 26daa655..1f224951 100644
--- a/package.json
+++ b/package.json
@@ -6,6 +6,7 @@
     "build": "ncc build --source-map --license licenses.txt src/main.ts",
     "test": "jest"
   },
+  "type": "module",
   "dependencies": {
     "@actions/core": "1.10.1",
     "@actions/github": "6.0.0",
@@ -13,6 +14,7 @@
     "@octokit/request-error": "5.1.0"
   },
   "devDependencies": {
+    "@tsconfig/node20": "^20.1.4",
     "@types/jest": "29.5.12",
     "@types/node": "20.12.7",
     "@vercel/ncc": "0.38.1",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 5a036abe..b1cdc93a 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -21,6 +21,9 @@ importers:
         specifier: 5.1.0
         version: 5.1.0
     devDependencies:
+      '@tsconfig/node20':
+        specifier: ^20.1.4
+        version: 20.1.4
       '@types/jest':
         specifier: 29.5.12
         version: 29.5.12
@@ -455,6 +458,9 @@ packages:
   '@sinonjs/fake-timers@10.3.0':
     resolution: {integrity: sha512-V4BG07kuYSUkTCSBHG8G8TNhM+F19jXFWnQtzj+we8DrkpSBCee9Z3Ms8yiGer/dlmhe35/Xdgyo3/0rQKg7YA==}
 
+  '@tsconfig/node20@20.1.4':
+    resolution: {integrity: sha512-sqgsT69YFeLWf5NtJ4Xq/xAF8p4ZQHlmGW74Nu2tD4+g5fAsposc4ZfaaPixVu4y01BEiDCWLRDCvDM5JOsRxg==}
+
   '@types/babel__core@7.20.5':
     resolution: {integrity: sha512-qoQprZvz5wQFJwMDqeseRXWv3rqMvhgpbXFfVyWhbx9X47POIA6i/+dXefEmZKoAgOaTdaIgNSMqMIU61yRyzA==}
 
@@ -2296,6 +2302,8 @@ snapshots:
     dependencies:
       '@sinonjs/commons': 3.0.1
 
+  '@tsconfig/node20@20.1.4': {}
+
   '@types/babel__core@7.20.5':
     dependencies:
       '@babel/parser': 7.24.0
diff --git a/src/body.ts b/src/body.ts
index 540902f2..b749b63b 100644
--- a/src/body.ts
+++ b/src/body.ts
@@ -1,6 +1,6 @@
 import * as core from '@actions/core'
 import * as github from '@actions/github'
-import { Issue, Octokit } from './types'
+import { Issue, Octokit } from './types.js'
 
 export const appendOrUpdateBody = async (octokit: Octokit, issue: Issue, content: string) => {
   let fetchedBody = issue.body
diff --git a/src/github.ts b/src/github.ts
index fd71b3d7..de31c993 100644
--- a/src/github.ts
+++ b/src/github.ts
@@ -1,7 +1,5 @@
-import { getOctokitOptions, GitHub } from '@actions/github/lib/utils'
+import * as github from '@actions/github'
 import * as pluginRetry from '@octokit/plugin-retry'
+import { Octokit } from './types.js'
 
-export const getOctokit = (token: string) => {
-  const MyOctokit = GitHub.plugin(pluginRetry.retry)
-  return new MyOctokit(getOctokitOptions(token))
-}
+export const getOctokit = (token: string): Octokit => github.getOctokit(token, undefined, pluginRetry.retry)
diff --git a/src/main.ts b/src/main.ts
index 09a427e4..8bbbdd5e 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,5 +1,5 @@
 import * as core from '@actions/core'
-import { run } from './run'
+import { run } from './run.js'
 
 const main = async (): Promise<void> => {
   await run({
diff --git a/src/run.ts b/src/run.ts
index 7375ae60..31d715c3 100644
--- a/src/run.ts
+++ b/src/run.ts
@@ -1,9 +1,9 @@
 import * as core from '@actions/core'
 import * as github from '@actions/github'
 import { RequestError } from '@octokit/request-error'
-import { appendOrUpdateBody } from './body'
-import { getOctokit } from './github'
-import { Issue, Octokit } from './types'
+import { appendOrUpdateBody } from './body.js'
+import { getOctokit } from './github.js'
+import { Issue, Octokit } from './types.js'
 
 export type Inputs = {
   issueNumbers: number[]
diff --git a/src/types.ts b/src/types.ts
index 75c9f0f6..a54a19dc 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,6 +1,6 @@
-import { GitHub } from '@actions/github/lib/utils'
+import * as github from '@actions/github'
 
-export type Octokit = InstanceType<typeof GitHub>
+export type Octokit = ReturnType<typeof github.getOctokit>
 
 export type Issue = {
   owner: string
diff --git a/tests/body.test.ts b/tests/body.test.ts
index b2b3acae..11db3343 100644
--- a/tests/body.test.ts
+++ b/tests/body.test.ts
@@ -1,4 +1,4 @@
-import { computeBody } from '../src/body'
+import { computeBody } from '../src/body.js'
 
 const marker = '<!-- marker -->'
 
diff --git a/tests/run.test.ts b/tests/run.test.ts
index 36d10a2d..18637899 100644
--- a/tests/run.test.ts
+++ b/tests/run.test.ts
@@ -1,4 +1,4 @@
-import { run } from '../src/run'
+import { run } from '../src/run.js'
 import { RequestError } from '@octokit/request-error'
 
 const octokitMock = {
diff --git a/tsconfig.json b/tsconfig.json
index d852dfc1..92ebc1fd 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,9 +1,4 @@
 {
-  "compilerOptions": {
-    "target": "es6",
-    "module": "commonjs",
-    "strict": true,
-    "outDir": "./lib",
-    "rootDirs": ["./src"],
-  }
+  "$schema": "https://json.schemastore.org/tsconfig",
+  "extends": "@tsconfig/node20/tsconfig.json"
 }