diff --git a/packages/commonjs/package.json b/packages/commonjs/package.json
index f2b352869..0c660a314 100644
--- a/packages/commonjs/package.json
+++ b/packages/commonjs/package.json
@@ -64,7 +64,7 @@
   "dependencies": {
     "@rollup/pluginutils": "^5.0.1",
     "commondir": "^1.0.1",
-    "estree-walker": "^2.0.2",
+    "estree-walker": "^3.0.3",
     "fdir": "^6.2.0",
     "is-reference": "1.2.1",
     "magic-string": "^0.30.3",
diff --git a/packages/commonjs/test/fixtures/samples/caching/rollupWorker.js b/packages/commonjs/test/fixtures/samples/caching/rollupWorker.js
index eb7e39ea6..ec0084819 100644
--- a/packages/commonjs/test/fixtures/samples/caching/rollupWorker.js
+++ b/packages/commonjs/test/fixtures/samples/caching/rollupWorker.js
@@ -2,12 +2,11 @@ const { workerData, parentPort } = require('worker_threads');
 
 const { rollup } = require('rollup');
 
-const commonjs = require('../../../..');
-const { getCodeFromBundle } = require('../../../helpers/util');
-
 generateCode(workerData);
 
 async function generateCode(cache) {
+  const commonjs = (await import('current-package')).default;
+  const { getCodeFromBundle } = await import('../../../helpers/util.mjs');
   const code = await getCodeFromBundle(
     await rollup({
       input: 'fixtures/samples/caching/main.js',
diff --git a/packages/commonjs/test/form.js b/packages/commonjs/test/form.mjs
similarity index 90%
rename from packages/commonjs/test/form.js
rename to packages/commonjs/test/form.mjs
index ba1534370..ea23210d0 100644
--- a/packages/commonjs/test/form.js
+++ b/packages/commonjs/test/form.mjs
@@ -1,14 +1,18 @@
 /* eslint-disable global-require, import/no-dynamic-require, no-console */
 
-const fs = require('fs');
-const path = require('path');
+import * as fs from 'fs';
+import { createRequire } from 'module';
+import * as path from 'path';
+import { fileURLToPath } from 'url';
 
-const acorn = require('acorn');
-const test = require('ava');
+import * as acorn from 'acorn';
+import test from 'ava';
 
-const { commonjs } = require('./helpers/util.js');
+import { commonjs } from './helpers/util.mjs';
 
-process.chdir(__dirname);
+const require = createRequire(import.meta.url);
+
+process.chdir(fileURLToPath(new URL('.', import.meta.url)));
 
 const transformContext = {
   error: (base, props) => {
diff --git a/packages/commonjs/test/function.js b/packages/commonjs/test/function.mjs
similarity index 79%
rename from packages/commonjs/test/function.js
rename to packages/commonjs/test/function.mjs
index b8701ef74..a71fca11a 100644
--- a/packages/commonjs/test/function.js
+++ b/packages/commonjs/test/function.mjs
@@ -1,13 +1,17 @@
 /* eslint-disable global-require, import/no-dynamic-require, no-console */
 
-const { readdirSync } = require('fs');
+import { readdirSync } from 'fs';
+import { createRequire } from 'module';
+import { fileURLToPath } from 'url';
 
-const test = require('ava');
-const { rollup } = require('rollup');
+import test from 'ava';
+import { rollup } from 'rollup';
 
-const { commonjs, getCodeMapFromBundle, runCodeSplitTest } = require('./helpers/util');
+import { commonjs, getCodeMapFromBundle, runCodeSplitTest } from './helpers/util.mjs';
 
-process.chdir(__dirname);
+const require = createRequire(import.meta.url);
+
+process.chdir(fileURLToPath(new URL('.', import.meta.url)));
 
 readdirSync('./fixtures/function').forEach((dir) => {
   let config;
diff --git a/packages/commonjs/test/helpers/util.js b/packages/commonjs/test/helpers/util.mjs
similarity index 77%
rename from packages/commonjs/test/helpers/util.js
rename to packages/commonjs/test/helpers/util.mjs
index 4d8bb2fda..cbb7ade53 100644
--- a/packages/commonjs/test/helpers/util.js
+++ b/packages/commonjs/test/helpers/util.mjs
@@ -1,13 +1,15 @@
-const path = require('path');
+import { createRequire } from 'module';
+import * as path from 'path';
 
-const commonjsPlugin = require('../..');
+import commonjsPlugin from 'current-package';
 
-function commonjs(options) {
-  delete require.cache[require.resolve('../..')];
+const require = createRequire(import.meta.url);
+
+export function commonjs(options) {
   return commonjsPlugin(options);
 }
 
-function normalizePathSlashes(path) {
+export function normalizePathSlashes(path) {
   return path.replace(/\\/g, '/');
 }
 
@@ -27,7 +29,7 @@ function requireWithContext(code, context) {
   return contextWithExports.module.exports;
 }
 
-function runCodeSplitTest(codeMap, t, entryName = 'main.js', configContext = {}) {
+export function runCodeSplitTest(codeMap, t, entryName = 'main.js', configContext = {}) {
   const requireFromOutputVia = (importer) => (importee) => {
     const outputId = path.posix.join(path.posix.dirname(importer), importee);
     const code = codeMap[outputId];
@@ -63,7 +65,7 @@ function runCodeSplitTest(codeMap, t, entryName = 'main.js', configContext = {})
   return { exports, global };
 }
 
-async function getCodeMapFromBundle(bundle, options = {}) {
+export async function getCodeMapFromBundle(bundle, options = {}) {
   const generated = await bundle.generate({
     interop: 'compat',
     exports: 'auto',
@@ -77,21 +79,12 @@ async function getCodeMapFromBundle(bundle, options = {}) {
   return codeMap;
 }
 
-async function getCodeFromBundle(bundle, customOptions = {}) {
+export async function getCodeFromBundle(bundle, customOptions = {}) {
   const options = { exports: 'auto', format: 'cjs', ...customOptions };
   return (await bundle.generate(options)).output[0].code;
 }
 
-async function executeBundle(bundle, t, { context, exports, testEntry = 'main.js' } = {}) {
+export async function executeBundle(bundle, t, { context, exports, testEntry = 'main.js' } = {}) {
   const codeMap = await getCodeMapFromBundle(bundle, exports ? { exports } : {});
   return runCodeSplitTest(codeMap, t, testEntry, context);
 }
-
-module.exports = {
-  commonjs,
-  executeBundle,
-  getCodeFromBundle,
-  getCodeMapFromBundle,
-  normalizePathSlashes,
-  runCodeSplitTest
-};
diff --git a/packages/commonjs/test/node_modules/current-package b/packages/commonjs/test/node_modules/current-package
new file mode 120000
index 000000000..6581736d6
--- /dev/null
+++ b/packages/commonjs/test/node_modules/current-package
@@ -0,0 +1 @@
+../../
\ No newline at end of file
diff --git a/packages/commonjs/test/snapshots/function.js.md b/packages/commonjs/test/snapshots/function.mjs.md
similarity index 99%
rename from packages/commonjs/test/snapshots/function.js.md
rename to packages/commonjs/test/snapshots/function.mjs.md
index 758c8aa3f..69dd02297 100644
--- a/packages/commonjs/test/snapshots/function.js.md
+++ b/packages/commonjs/test/snapshots/function.mjs.md
@@ -1,6 +1,6 @@
-# Snapshot report for `test/function.js`
+# Snapshot report for `test/function.mjs`
 
-The actual snapshot is saved in `function.js.snap`.
+The actual snapshot is saved in `function.mjs.snap`.
 
 Generated by [AVA](https://avajs.dev).
 
diff --git a/packages/commonjs/test/snapshots/function.js.snap b/packages/commonjs/test/snapshots/function.mjs.snap
similarity index 100%
rename from packages/commonjs/test/snapshots/function.js.snap
rename to packages/commonjs/test/snapshots/function.mjs.snap
diff --git a/packages/commonjs/test/snapshots/test.js.md b/packages/commonjs/test/snapshots/test.mjs.md
similarity index 99%
rename from packages/commonjs/test/snapshots/test.js.md
rename to packages/commonjs/test/snapshots/test.mjs.md
index b12fd1200..4886edad6 100644
--- a/packages/commonjs/test/snapshots/test.js.md
+++ b/packages/commonjs/test/snapshots/test.mjs.md
@@ -1,6 +1,6 @@
-# Snapshot report for `test/test.js`
+# Snapshot report for `test/test.mjs`
 
-The actual snapshot is saved in `test.js.snap`.
+The actual snapshot is saved in `test.mjs.snap`.
 
 Generated by [AVA](https://avajs.dev).
 
diff --git a/packages/commonjs/test/snapshots/test.js.snap b/packages/commonjs/test/snapshots/test.mjs.snap
similarity index 100%
rename from packages/commonjs/test/snapshots/test.js.snap
rename to packages/commonjs/test/snapshots/test.mjs.snap
diff --git a/packages/commonjs/test/test.js b/packages/commonjs/test/test.mjs
similarity index 98%
rename from packages/commonjs/test/test.js
rename to packages/commonjs/test/test.mjs
index 1ef56aa0d..e4bca4cf5 100644
--- a/packages/commonjs/test/test.js
+++ b/packages/commonjs/test/test.mjs
@@ -1,27 +1,31 @@
 /* eslint-disable line-comment-position, no-new-func, no-undefined */
 
-const os = require('os');
-const path = require('path');
-
-const { nodeResolve } = require('@rollup/plugin-node-resolve');
-const test = require('ava');
-const { getLocator } = require('locate-character');
-const { rollup } = require('rollup');
-const { install } = require('source-map-support');
-
-const { testBundle } = require('../../../util/test');
-
-const { peerDependencies } = require('../package.json');
-
-const {
+import { createRequire } from 'module';
+import * as os from 'os';
+import * as path from 'path';
+import { fileURLToPath } from 'url';
+
+import { nodeResolve } from '@rollup/plugin-node-resolve';
+import test from 'ava';
+import { getLocator } from 'locate-character';
+import { rollup } from 'rollup';
+import { install } from 'source-map-support';
+
+import {
   commonjs,
   executeBundle,
   getCodeFromBundle,
   normalizePathSlashes
-} = require('./helpers/util.js');
+} from './helpers/util.mjs';
+
+const require = createRequire(import.meta.url);
+
+const { peerDependencies } = require('../package.json');
+
+const { testBundle } = require('../../../util/test.js');
 
 install();
-test.beforeEach(() => process.chdir(__dirname));
+test.beforeEach(() => process.chdir(fileURLToPath(new URL('.', import.meta.url))));
 
 const loader = (modules) => {
   return {
@@ -228,7 +232,7 @@ test.serial('handles symlinked node_modules with preserveSymlinks: false', (t) =
 
   // ensure we resolve starting from a directory with
   // symlinks in node_modules.
-  process.chdir(path.join(__dirname, 'fixtures/samples/symlinked-node-modules'));
+  process.chdir(fileURLToPath(new URL('fixtures/samples/symlinked-node-modules', import.meta.url)));
 
   return t.notThrowsAsync(
     rollup({
@@ -652,7 +656,7 @@ if (Number(/^v(\d+)/.exec(process.version)[1]) >= 12) {
     // We do a second run in a worker so that all internal state is cleared
     const { Worker } = await import('worker_threads');
     const getRollupUpCodeWithCache = new Worker(
-      path.join(__dirname, 'fixtures/samples/caching/rollupWorker.js'),
+      fileURLToPath(new URL('fixtures/samples/caching/rollupWorker.js', import.meta.url)),
       {
         workerData: cache
       }
diff --git a/packages/dynamic-import-vars/package.json b/packages/dynamic-import-vars/package.json
index 305439fc8..66bbc3ff9 100644
--- a/packages/dynamic-import-vars/package.json
+++ b/packages/dynamic-import-vars/package.json
@@ -65,7 +65,7 @@
   "dependencies": {
     "@rollup/pluginutils": "^5.0.1",
     "astring": "^1.8.5",
-    "estree-walker": "^2.0.2",
+    "estree-walker": "^3.0.3",
     "fast-glob": "^3.2.12",
     "magic-string": "^0.30.3"
   },
diff --git a/packages/dynamic-import-vars/test/rollup-plugin-dynamic-import-vars.test.js b/packages/dynamic-import-vars/test/rollup-plugin-dynamic-import-vars.test.mjs
similarity index 65%
rename from packages/dynamic-import-vars/test/rollup-plugin-dynamic-import-vars.test.js
rename to packages/dynamic-import-vars/test/rollup-plugin-dynamic-import-vars.test.mjs
index 58c40091c..dd09c6809 100644
--- a/packages/dynamic-import-vars/test/rollup-plugin-dynamic-import-vars.test.js
+++ b/packages/dynamic-import-vars/test/rollup-plugin-dynamic-import-vars.test.mjs
@@ -1,13 +1,16 @@
 /* eslint-disable import/no-unresolved */
 
-const { join } = require('path');
+import { posix } from 'path';
+import { fileURLToPath } from 'url';
 
-const test = require('ava');
-const { rollup } = require('rollup');
+import test from 'ava';
+import { rollup } from 'rollup';
 
-const dynamicImportVars = require('current-package');
+import dynamicImportVars from 'current-package';
 
-process.chdir(join(__dirname, 'fixtures'));
+const DIRNAME = fileURLToPath(new URL('.', import.meta.url));
+
+process.chdir(fileURLToPath(new URL('fixtures', import.meta.url)));
 
 test('single dir', async (t) => {
   const bundle = await rollup({
@@ -16,9 +19,9 @@ test('single dir', async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
   const expectedFiles = [
-    require.resolve('./fixtures/fixture-single-dir.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-1.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-2.js')
+    posix.resolve(DIRNAME, './fixtures/fixture-single-dir.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-2.js')
   ];
 
   t.deepEqual(
@@ -35,12 +38,12 @@ test('multiple dirs', async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
   const expectedFiles = [
-    require.resolve('./fixtures/fixture-multiple-dirs.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-1.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-2.js'),
-    require.resolve('./fixtures/module-dir-b/module-b-1.js'),
-    require.resolve('./fixtures/module-dir-b/module-b-2.js'),
-    require.resolve('./fixtures/sub-dir/fixture-upwards-path.js')
+    posix.resolve(DIRNAME, './fixtures/fixture-multiple-dirs.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-2.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-b/module-b-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-b/module-b-2.js'),
+    posix.resolve(DIRNAME, './fixtures/sub-dir/fixture-upwards-path.js')
   ];
 
   t.deepEqual(
@@ -57,9 +60,9 @@ test('upwards dir path', async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
   const expectedFiles = [
-    require.resolve('./fixtures/sub-dir/fixture-upwards-path.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-1.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-2.js')
+    posix.resolve(DIRNAME, './fixtures/sub-dir/fixture-upwards-path.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-2.js')
   ];
 
   t.deepEqual(
@@ -76,11 +79,11 @@ test('complex concatenation', async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
   const expectedFiles = [
-    require.resolve('./fixtures/fixture-complex-concat.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-1.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-2.js'),
-    require.resolve('./fixtures/module-dir-b/module-b-1.js'),
-    require.resolve('./fixtures/module-dir-b/module-b-2.js')
+    posix.resolve(DIRNAME, './fixtures/fixture-complex-concat.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-2.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-b/module-b-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-b/module-b-2.js')
   ];
 
   t.deepEqual(
@@ -97,9 +100,9 @@ test('own directory', async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
   const expectedFiles = [
-    require.resolve('./fixtures/fixture-own-dir.js'),
-    require.resolve('./fixtures/root-module-a.js'),
-    require.resolve('./fixtures/root-module-b.js')
+    posix.resolve(DIRNAME, './fixtures/fixture-own-dir.js'),
+    posix.resolve(DIRNAME, './fixtures/root-module-a.js'),
+    posix.resolve(DIRNAME, './fixtures/root-module-b.js')
   ];
 
   t.deepEqual(
@@ -116,12 +119,12 @@ test('multiple dynamic imports', async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
   const expectedFiles = [
-    require.resolve('./fixtures/fixture-multiple-imports.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-1.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-2.js'),
-    require.resolve('./fixtures/module-dir-b/module-b-1.js'),
-    require.resolve('./fixtures/module-dir-b/module-b-2.js'),
-    require.resolve('./fixtures/sub-dir/fixture-upwards-path.js')
+    posix.resolve(DIRNAME, './fixtures/fixture-multiple-imports.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-2.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-b/module-b-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-b/module-b-2.js'),
+    posix.resolve(DIRNAME, './fixtures/sub-dir/fixture-upwards-path.js')
   ];
 
   t.deepEqual(
@@ -138,8 +141,8 @@ test("doesn't change imports that should not be changed", async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
   const expectedFiles = [
-    require.resolve('./fixtures/fixture-unchanged.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-2.js')
+    posix.resolve(DIRNAME, './fixtures/fixture-unchanged.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-2.js')
   ];
 
   t.deepEqual(
@@ -160,7 +163,7 @@ test('can exclude files', async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
 
-  const expectedFiles = [require.resolve('./fixtures/fixture-excluded.js')];
+  const expectedFiles = [posix.resolve(DIRNAME, './fixtures/fixture-excluded.js')];
 
   t.deepEqual(
     expectedFiles,
@@ -193,9 +196,9 @@ test('dynamic imports assertions', async (t) => {
   });
   const { output } = await bundle.generate({ format: 'es' });
   const expectedFiles = [
-    require.resolve('./fixtures/fixture-assert.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-1.js'),
-    require.resolve('./fixtures/module-dir-a/module-a-2.js')
+    posix.resolve(DIRNAME, './fixtures/fixture-assert.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-1.js'),
+    posix.resolve(DIRNAME, './fixtures/module-dir-a/module-a-2.js')
   ];
 
   t.deepEqual(
@@ -228,7 +231,8 @@ test('throws if no files in dir when `errorWhenNoFilesFound` is set', async (t)
   } catch (error) {
     t.deepEqual(
       error.message,
-      `No files found in ./module-dir-c/*.js when trying to dynamically load concatted string from ${require.resolve(
+      `No files found in ./module-dir-c/*.js when trying to dynamically load concatted string from ${posix.resolve(
+        DIRNAME,
         './fixtures/fixture-no-files.js'
       )}`
     );
@@ -245,7 +249,8 @@ test('warns if no files in dir when `errorWhenNoFilesFound` and `warnOnError` ar
     onwarn(warning) {
       t.deepEqual(
         warning.message,
-        `No files found in ./module-dir-c/*.js when trying to dynamically load concatted string from ${require.resolve(
+        `No files found in ./module-dir-c/*.js when trying to dynamically load concatted string from ${posix.resolve(
+          DIRNAME,
           './fixtures/fixture-no-files.js'
         )}`
       );
diff --git a/packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.js.md b/packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.mjs.md
similarity index 99%
rename from packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.js.md
rename to packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.mjs.md
index 0889053e5..4d6d8928e 100644
--- a/packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.js.md
+++ b/packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.mjs.md
@@ -1,6 +1,6 @@
-# Snapshot report for `test/rollup-plugin-dynamic-import-vars.test.js`
+# Snapshot report for `test/rollup-plugin-dynamic-import-vars.test.mjs`
 
-The actual snapshot is saved in `rollup-plugin-dynamic-import-vars.test.js.snap`.
+The actual snapshot is saved in `rollup-plugin-dynamic-import-vars.test.mjs.snap`.
 
 Generated by [AVA](https://avajs.dev).
 
diff --git a/packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.js.snap b/packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.mjs.snap
similarity index 100%
rename from packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.js.snap
rename to packages/dynamic-import-vars/test/snapshots/rollup-plugin-dynamic-import-vars.test.mjs.snap
diff --git a/packages/inject/package.json b/packages/inject/package.json
index 7ecabd25f..09dd55a17 100644
--- a/packages/inject/package.json
+++ b/packages/inject/package.json
@@ -62,7 +62,7 @@
   },
   "dependencies": {
     "@rollup/pluginutils": "^5.0.1",
-    "estree-walker": "^2.0.2",
+    "estree-walker": "^3.0.3",
     "magic-string": "^0.30.3"
   },
   "devDependencies": {
diff --git a/packages/inject/test/node_modules/current-package b/packages/inject/test/node_modules/current-package
new file mode 120000
index 000000000..6581736d6
--- /dev/null
+++ b/packages/inject/test/node_modules/current-package
@@ -0,0 +1 @@
+../../
\ No newline at end of file
diff --git a/packages/inject/test/snapshots/test.js.md b/packages/inject/test/snapshots/test.mjs.md
similarity index 97%
rename from packages/inject/test/snapshots/test.js.md
rename to packages/inject/test/snapshots/test.mjs.md
index b82323573..5c2f437a3 100644
--- a/packages/inject/test/snapshots/test.js.md
+++ b/packages/inject/test/snapshots/test.mjs.md
@@ -1,6 +1,6 @@
-# Snapshot report for `test/test.js`
+# Snapshot report for `test/test.mjs`
 
-The actual snapshot is saved in `test.js.snap`.
+The actual snapshot is saved in `test.mjs.snap`.
 
 Generated by [AVA](https://avajs.dev).
 
diff --git a/packages/inject/test/snapshots/test.js.snap b/packages/inject/test/snapshots/test.mjs.snap
similarity index 100%
rename from packages/inject/test/snapshots/test.js.snap
rename to packages/inject/test/snapshots/test.mjs.snap
diff --git a/packages/inject/test/test.js b/packages/inject/test/test.mjs
similarity index 93%
rename from packages/inject/test/test.js
rename to packages/inject/test/test.mjs
index 5f5ee27e3..452e10d77 100644
--- a/packages/inject/test/test.js
+++ b/packages/inject/test/test.mjs
@@ -1,11 +1,11 @@
-const fs = require('fs');
-const path = require('path');
-const os = require('os');
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
 
-const acorn = require('acorn');
-const test = require('ava');
+import * as acorn from 'acorn';
+import test from 'ava';
 
-const inject = require('..');
+import inject from 'current-package';
 
 const compare = (t, fixture, options) => {
   const filename = path.resolve(`test/fixtures/${fixture}/input.js`);
diff --git a/packages/pluginutils/package.json b/packages/pluginutils/package.json
index 2745ddcce..6650fada1 100644
--- a/packages/pluginutils/package.json
+++ b/packages/pluginutils/package.json
@@ -62,7 +62,7 @@
   },
   "dependencies": {
     "@types/estree": "^1.0.0",
-    "estree-walker": "^2.0.2",
+    "estree-walker": "^3.0.3",
     "picomatch": "^2.3.1"
   },
   "devDependencies": {
diff --git a/packages/pluginutils/src/attachScopes.ts b/packages/pluginutils/src/attachScopes.ts
index fc6392ddb..6800deac1 100755
--- a/packages/pluginutils/src/attachScopes.ts
+++ b/packages/pluginutils/src/attachScopes.ts
@@ -106,7 +106,7 @@ const attachScopes: AttachScopes = function attachScopes(ast, propertyName = 'sc
       }
 
       // create new block scope
-      if (node.type === 'BlockStatement' && !/Function/.test(parent.type)) {
+      if (node.type === 'BlockStatement' && parent && !/Function/.test(parent.type)) {
         newScope = new Scope({
           parent: scope,
           block: true
diff --git a/packages/pluginutils/types/index.d.ts b/packages/pluginutils/types/index.d.ts
index 4bdf3a2a6..8f50e0c8f 100755
--- a/packages/pluginutils/types/index.d.ts
+++ b/packages/pluginutils/types/index.d.ts
@@ -1,10 +1,10 @@
-import type { BaseNode } from 'estree';
+import type { Node } from 'estree';
 
 export interface AttachedScope {
   parent?: AttachedScope;
   isBlockScope: boolean;
   declarations: { [key: string]: boolean };
-  addDeclaration(node: BaseNode, isBlockDeclaration: boolean, isVar: boolean): void;
+  addDeclaration(node: Node, isBlockDeclaration: boolean, isVar: boolean): void;
   contains(name: string): boolean;
 }
 
@@ -37,7 +37,7 @@ export function addExtension(filename: string, ext?: string): string;
  * Each `Scope` object has a `scope.contains(name)` method that returns `true`
  * if a given name is defined in the current scope or a parent scope.
  */
-export function attachScopes(ast: BaseNode, propertyName?: string): AttachedScope;
+export function attachScopes(ast: Node, propertyName?: string): AttachedScope;
 
 /**
  * Constructs a filter function which can be used to determine whether or not
@@ -66,7 +66,7 @@ export function dataToEsm(data: unknown, options?: DataToEsmOptions): string;
  * Extracts the names of all assignment targets based upon specified patterns.
  * @param param An `acorn` AST Node.
  */
-export function extractAssignedNames(param: BaseNode): string[];
+export function extractAssignedNames(param: Node): string[];
 
 /**
  * Constructs a bundle-safe identifier from a `string`.
diff --git a/packages/strip/package.json b/packages/strip/package.json
index b3272cede..d80ef934d 100644
--- a/packages/strip/package.json
+++ b/packages/strip/package.json
@@ -56,7 +56,7 @@
   },
   "dependencies": {
     "@rollup/pluginutils": "^5.0.1",
-    "estree-walker": "^2.0.2",
+    "estree-walker": "^3.0.3",
     "magic-string": "^0.30.3"
   },
   "devDependencies": {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 3f75e203e..57b264073 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -203,8 +203,8 @@ importers:
         specifier: ^1.0.1
         version: 1.0.1
       estree-walker:
-        specifier: ^2.0.2
-        version: 2.0.2
+        specifier: ^3.0.3
+        version: 3.0.3
       fdir:
         specifier: ^6.2.0
         version: 6.3.0(picomatch@4.0.2)
@@ -293,8 +293,8 @@ importers:
         specifier: ^1.8.5
         version: 1.8.5
       estree-walker:
-        specifier: ^2.0.2
-        version: 2.0.2
+        specifier: ^3.0.3
+        version: 3.0.3
       fast-glob:
         specifier: ^3.2.12
         version: 3.2.12
@@ -409,8 +409,8 @@ importers:
         specifier: ^5.0.1
         version: 5.0.1(rollup@4.0.0-24)
       estree-walker:
-        specifier: ^2.0.2
-        version: 2.0.2
+        specifier: ^3.0.3
+        version: 3.0.3
       magic-string:
         specifier: ^0.30.3
         version: 0.30.3
@@ -532,10 +532,10 @@ importers:
     dependencies:
       '@types/estree':
         specifier: ^1.0.0
-        version: 1.0.0
+        version: 1.0.6
       estree-walker:
-        specifier: ^2.0.2
-        version: 2.0.2
+        specifier: ^3.0.3
+        version: 3.0.3
       picomatch:
         specifier: ^2.3.1
         version: 2.3.1
@@ -621,8 +621,8 @@ importers:
         specifier: ^5.0.1
         version: 5.0.1(rollup@4.0.0-24)
       estree-walker:
-        specifier: ^2.0.2
-        version: 2.0.2
+        specifier: ^3.0.3
+        version: 3.0.3
       magic-string:
         specifier: ^0.30.3
         version: 0.30.3
@@ -1772,6 +1772,9 @@ packages:
   '@types/estree@1.0.0':
     resolution: {integrity: sha512-WulqXMDUTYAXCjZnk6JtIHPigp55cVtDgDrO2gHRwhyJto21+1zbVCtOYB2L1F9w4qCQ0rOGWBnBe0FNTiEJIQ==}
 
+  '@types/estree@1.0.6':
+    resolution: {integrity: sha512-AYnb1nQyY49te+VRAVgmzfcgjYS91mY5P0TKUDCLEM+gNnA+3T6rWITXRLYCpahpqSQbN5cE+gHpnPyXjHWxcw==}
+
   '@types/http-cache-semantics@4.0.1':
     resolution: {integrity: sha512-SZs7ekbP8CN0txVG2xVRH6EgKmEm31BOxA07vkFaETzZz1xh+cbt8BcI0slpymvwhx5dlFnQG2rTlPVQn+iRPQ==}
 
@@ -2690,6 +2693,9 @@ packages:
   estree-walker@2.0.2:
     resolution: {integrity: sha512-Rfkk/Mp/DL7JVje3u18FxFujQlTNR2q6QfMSMB7AvCBx91NGj/ba3kCfza0f6dVDbw7YlRf/nDrn7pQrCCyQ/w==}
 
+  estree-walker@3.0.3:
+    resolution: {integrity: sha512-7RUKfXgSMMkzt6ZuXmqapOurLGPPfgj6l9uRZ7lRGolvk0y2yocc35LdcxKC5PQZdn2DMqioAQ2NoWcrTKmm6g==}
+
   esutils@2.0.3:
     resolution: {integrity: sha512-kVscqXk4OCp68SZ0dkgEKVi6/8ij300KBWTJq32P/dYeWTSwK41WyTxalN1eRmA5Z9UU/LX9D7FWSmV9SAYx6g==}
     engines: {node: '>=0.10.0'}
@@ -5623,7 +5629,7 @@ snapshots:
 
   '@rollup/pluginutils@5.1.0(rollup@4.0.0-24)':
     dependencies:
-      '@types/estree': 1.0.0
+      '@types/estree': 1.0.6
       estree-walker: 2.0.2
       picomatch: 2.3.1
     optionalDependencies:
@@ -5773,11 +5779,13 @@ snapshots:
 
   '@types/eslint@8.4.6':
     dependencies:
-      '@types/estree': 1.0.0
+      '@types/estree': 1.0.6
       '@types/json-schema': 7.0.11
 
   '@types/estree@1.0.0': {}
 
+  '@types/estree@1.0.6': {}
+
   '@types/http-cache-semantics@4.0.1': {}
 
   '@types/json-schema@7.0.11': {}
@@ -6923,6 +6931,10 @@ snapshots:
 
   estree-walker@2.0.2: {}
 
+  estree-walker@3.0.3:
+    dependencies:
+      '@types/estree': 1.0.6
+
   esutils@2.0.3: {}
 
   eventemitter3@4.0.7: {}
@@ -7305,7 +7317,7 @@ snapshots:
 
   is-reference@1.2.1:
     dependencies:
-      '@types/estree': 1.0.0
+      '@types/estree': 1.0.6
 
   is-regex@1.1.4:
     dependencies: