diff --git a/src/env.ts b/src/env.ts
index 0fe7f56d..b3457c47 100644
--- a/src/env.ts
+++ b/src/env.ts
@@ -1,6 +1,6 @@
 import { resolvePathSync, type ResolveOptions } from "mlly";
 import type { Preset, Environment, CreateEnvOptions } from "../lib/index.d.mts";
-import nodeCompatPreset from "./presets/nodeless";
+import nodeCompatPreset from "./presets/nodeless.ts";
 
 /**
  * Configure a target environment.
diff --git a/src/index.ts b/src/index.ts
index 556642c8..997bc0ad 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1 +1 @@
-export { defineEnv } from "./env";
+export { defineEnv } from "./env.ts";
diff --git a/src/presets/node.ts b/src/presets/node.ts
index 73fa1ed7..ed7f2d42 100644
--- a/src/presets/node.ts
+++ b/src/presets/node.ts
@@ -1,4 +1,4 @@
-import { builtinModules } from "../runtime/node/module";
+import { builtinModules } from "../runtime/node/module.ts";
 import type { Preset } from "../../lib/index.d.mts";
 import { version } from "../../package.json";
 
diff --git a/src/presets/nodeless.ts b/src/presets/nodeless.ts
index 467dece0..20c22fb7 100644
--- a/src/presets/nodeless.ts
+++ b/src/presets/nodeless.ts
@@ -1,5 +1,5 @@
-import { mapArrToVal } from "./utils";
-import { builtinModules } from "../runtime/node/module";
+import { mapArrToVal } from "./utils.ts";
+import { builtinModules } from "../runtime/node/module.ts";
 import type { Preset } from "../../lib/index.d.mts";
 import { version } from "../../package.json";
 
diff --git a/src/runtime/_internal/utils.ts b/src/runtime/_internal/utils.ts
index a2db7e0b..15f2850e 100644
--- a/src/runtime/_internal/utils.ts
+++ b/src/runtime/_internal/utils.ts
@@ -1,4 +1,4 @@
-import type { HeadersObject } from "./types";
+import type { HeadersObject } from "./types.ts";
 
 /*@__NO_SIDE_EFFECTS__*/
 export function rawHeaders(headers: HeadersObject) {
diff --git a/src/runtime/node/assert.ts b/src/runtime/node/assert.ts
index be6d32cb..e91c8836 100644
--- a/src/runtime/node/assert.ts
+++ b/src/runtime/node/assert.ts
@@ -25,7 +25,7 @@
 import type nodeAssert from "node:assert";
 
 import { isEqual as _ohashIsEqual } from "ohash";
-import { notImplementedClass } from "../_internal/utils";
+import { notImplementedClass } from "../_internal/utils.ts";
 
 // TODO: Implement Error classes
 const ERR_AMBIGUOUS_ARGUMENT = Error;
diff --git a/src/runtime/node/assert/strict.ts b/src/runtime/node/assert/strict.ts
index 9ac99a21..f310fa84 100644
--- a/src/runtime/node/assert/strict.ts
+++ b/src/runtime/node/assert/strict.ts
@@ -21,7 +21,7 @@ import {
   notStrictEqual as notEqual,
   deepStrictEqual,
   deepStrictEqual as deepEqual,
-} from "../assert";
+} from "../assert.ts";
 
 export {
   AssertionError,
@@ -44,7 +44,7 @@ export {
   notStrictEqual as notEqual,
   deepStrictEqual,
   deepStrictEqual as deepEqual,
-} from "../assert";
+} from "../assert.ts";
 
 export default Object.assign(ok, {
   AssertionError,
diff --git a/src/runtime/node/async_hooks.ts b/src/runtime/node/async_hooks.ts
index f3901ede..ea2d00cd 100644
--- a/src/runtime/node/async_hooks.ts
+++ b/src/runtime/node/async_hooks.ts
@@ -1,15 +1,15 @@
 // https://nodejs.org/api/events.html
 import type asyncHooks from "node:async_hooks";
 
-import { AsyncLocalStorage } from "./internal/async_hooks/async-local-storage";
-import { AsyncResource } from "./internal/async_hooks/async-resource";
+import { AsyncLocalStorage } from "./internal/async_hooks/async-local-storage.ts";
+import { AsyncResource } from "./internal/async_hooks/async-resource.ts";
 
-import * as asyncHook from "./internal/async_hooks/async-hook";
+import * as asyncHook from "./internal/async_hooks/async-hook.ts";
 
-export { AsyncLocalStorage } from "./internal/async_hooks/async-local-storage";
-export { AsyncResource } from "./internal/async_hooks/async-resource";
+export { AsyncLocalStorage } from "./internal/async_hooks/async-local-storage.ts";
+export { AsyncResource } from "./internal/async_hooks/async-resource.ts";
 
-export * from "./internal/async_hooks/async-hook";
+export * from "./internal/async_hooks/async-hook.ts";
 
 export default {
   AsyncLocalStorage,
diff --git a/src/runtime/node/buffer.ts b/src/runtime/node/buffer.ts
index 4f0867ea..cc3aad87 100644
--- a/src/runtime/node/buffer.ts
+++ b/src/runtime/node/buffer.ts
@@ -1,23 +1,23 @@
 // https://nodejs.org/api/buffer.html
 import type buffer from "node:buffer";
-import { notImplemented } from "../_internal/utils";
+import { notImplemented } from "../_internal/utils.ts";
 import {
   Buffer as _Buffer,
   kMaxLength,
   INSPECT_MAX_BYTES,
   SlowBuffer,
-} from "./internal/buffer/buffer";
-import { File } from "./internal/buffer/file";
+} from "./internal/buffer/buffer.ts";
+import { File } from "./internal/buffer/file.ts";
 
 export {
   kMaxLength,
   INSPECT_MAX_BYTES,
   SlowBuffer,
-} from "./internal/buffer/buffer";
+} from "./internal/buffer/buffer.ts";
 
 export const Buffer = globalThis.Buffer || _Buffer;
 
-export { File } from "./internal/buffer/file";
+export { File } from "./internal/buffer/file.ts";
 
 // @ts-expect-eerror https://github.com/unjs/unenv/issues/64
 export const Blob = globalThis.Blob as unknown as typeof buffer.Blob;
diff --git a/src/runtime/node/child_process.ts b/src/runtime/node/child_process.ts
index f69073ae..e95c9cac 100644
--- a/src/runtime/node/child_process.ts
+++ b/src/runtime/node/child_process.ts
@@ -1,4 +1,4 @@
-import { notImplemented, notImplementedClass } from "../_internal/utils";
+import { notImplemented, notImplementedClass } from "../_internal/utils.ts";
 import type child_process from "node:child_process";
 
 export const ChildProcess: typeof child_process.ChildProcess =
diff --git a/src/runtime/node/cluster.ts b/src/runtime/node/cluster.ts
index e557035a..24d507fb 100644
--- a/src/runtime/node/cluster.ts
+++ b/src/runtime/node/cluster.ts
@@ -1,6 +1,6 @@
 // Reference: https://github.com/nodejs/node/blob/main/lib/internal/cluster/primary.js
-import mock from "../mock/proxy";
-import { notImplemented } from "../_internal/utils";
+import mock from "../mock/proxy.ts";
+import { notImplemented } from "../_internal/utils.ts";
 import type nodeCluster from "node:cluster";
 import type {
   Cluster as NodeCluster,
diff --git a/src/runtime/node/console.ts b/src/runtime/node/console.ts
index d7c8bde6..f715755e 100644
--- a/src/runtime/node/console.ts
+++ b/src/runtime/node/console.ts
@@ -1,8 +1,8 @@
 import type console from "node:console";
 import { Writable } from "node:stream";
-import mock from "../mock/proxy";
-import noop from "../mock/noop";
-import { notImplemented } from "../_internal/utils";
+import mock from "../mock/proxy.ts";
+import noop from "../mock/noop.ts";
+import { notImplemented } from "../_internal/utils.ts";
 
 const _console = globalThis.console;
 
@@ -49,7 +49,7 @@ export const timeStamp: typeof console.timeStamp = _console?.timeStamp ?? noop;
 export const Console: typeof console.Console =
   _console?.Console ?? mock.__createMock__("console.Console");
 
-export { default as _times } from "../mock/proxy";
+export { default as _times } from "../mock/proxy.ts";
 
 export function context() {
   // TODO: Should be Console with all the methods
@@ -59,7 +59,7 @@ export function context() {
 export {
   default as _stdoutErrorHandler,
   default as _stderrErrorHandler,
-} from "../mock/noop";
+} from "../mock/noop.ts";
 
 export default {
   assert,
diff --git a/src/runtime/node/constants.ts b/src/runtime/node/constants.ts
index 4eec7b28..9b989b81 100644
--- a/src/runtime/node/constants.ts
+++ b/src/runtime/node/constants.ts
@@ -1,13 +1,13 @@
 // Mostly taken from: https://github.com/nodejs/node/blob/main/typings/internalBinding/constants.d.ts
 
 import type constants from "node:constants";
-import * as os from "./internal/constants/os";
-import * as fs from "./internal/constants/fs";
-import * as crypto from "./internal/constants/crypto";
+import * as os from "./internal/constants/os.ts";
+import * as fs from "./internal/constants/fs.ts";
+import * as crypto from "./internal/constants/crypto.ts";
 
-export * from "./internal/constants/os";
-export * from "./internal/constants/fs";
-export * from "./internal/constants/crypto";
+export * from "./internal/constants/os.ts";
+export * from "./internal/constants/fs.ts";
+export * from "./internal/constants/crypto.ts";
 
 export default <typeof constants>{
   ...crypto,
diff --git a/src/runtime/node/crypto.ts b/src/runtime/node/crypto.ts
index 53aa0175..dd6b3d14 100644
--- a/src/runtime/node/crypto.ts
+++ b/src/runtime/node/crypto.ts
@@ -1,12 +1,12 @@
 import type nodeCrypto from "node:crypto";
 
-import * as web from "./internal/crypto/web";
-import * as node from "./internal/crypto/node";
-import constants from "./internal/crypto/constants";
+import * as web from "./internal/crypto/web.ts";
+import * as node from "./internal/crypto/node.ts";
+import constants from "./internal/crypto/constants.ts";
 
-export * from "./internal/crypto/web";
-export * from "./internal/crypto/node";
-export { default as constants } from "./internal/crypto/constants";
+export * from "./internal/crypto/web.ts";
+export * from "./internal/crypto/node.ts";
+export { default as constants } from "./internal/crypto/constants.ts";
 
 export default {
   ...web,
diff --git a/src/runtime/node/dgram.ts b/src/runtime/node/dgram.ts
index c3457a93..daacc097 100644
--- a/src/runtime/node/dgram.ts
+++ b/src/runtime/node/dgram.ts
@@ -1,8 +1,8 @@
-import noop from "../mock/noop";
+import noop from "../mock/noop.ts";
 import type dgram from "node:dgram";
-import { Socket } from "./internal/dgram/socket";
+import { Socket } from "./internal/dgram/socket.ts";
 
-export { Socket } from "./internal/dgram/socket";
+export { Socket } from "./internal/dgram/socket.ts";
 
 export const _createSocketHandle = noop;
 
diff --git a/src/runtime/node/diagnostics_channel.ts b/src/runtime/node/diagnostics_channel.ts
index 1cec8d0d..7f28cce6 100644
--- a/src/runtime/node/diagnostics_channel.ts
+++ b/src/runtime/node/diagnostics_channel.ts
@@ -1,8 +1,11 @@
 import type diagnostics_channel from "node:diagnostics_channel";
-import { Channel, getChannels } from "./internal/diagnostics_channel/channel";
-import { TracingChannel } from "./internal/diagnostics_channel/tracing-channel";
+import {
+  Channel,
+  getChannels,
+} from "./internal/diagnostics_channel/channel.ts";
+import { TracingChannel } from "./internal/diagnostics_channel/tracing-channel.ts";
 
-export { Channel } from "./internal/diagnostics_channel/channel";
+export { Channel } from "./internal/diagnostics_channel/channel.ts";
 
 export const channel: typeof diagnostics_channel.channel = function (name) {
   const channels = getChannels();
diff --git a/src/runtime/node/dns.ts b/src/runtime/node/dns.ts
index 1a06f5f8..4dd0ac9f 100644
--- a/src/runtime/node/dns.ts
+++ b/src/runtime/node/dns.ts
@@ -1,12 +1,12 @@
-import noop from "../mock/noop";
-import mock from "../mock/proxy";
-import { notImplemented, notImplementedAsync } from "../_internal/utils";
+import noop from "../mock/noop.ts";
+import mock from "../mock/proxy.ts";
+import { notImplemented, notImplementedAsync } from "../_internal/utils.ts";
 import type dns from "node:dns";
-import promises from "./dns/promises";
-import * as constants from "./internal/dns/constants";
+import promises from "./dns/promises.ts";
+import * as constants from "./internal/dns/constants.ts";
 
-export * from "./internal/dns/constants";
-export * as promises from "./dns/promises";
+export * from "./internal/dns/constants.ts";
+export * as promises from "./dns/promises.ts";
 
 export const Resolver: typeof dns.Resolver =
   mock.__createMock__("dns.Resolver");
diff --git a/src/runtime/node/dns/promises.ts b/src/runtime/node/dns/promises.ts
index 4e5fb6f0..af7cd82e 100644
--- a/src/runtime/node/dns/promises.ts
+++ b/src/runtime/node/dns/promises.ts
@@ -1,9 +1,9 @@
-import noop from "../../mock/noop";
-import mock from "../../mock/proxy";
-import { notImplemented, notImplementedAsync } from "../../_internal/utils";
+import noop from "../../mock/noop.ts";
+import mock from "../../mock/proxy.ts";
+import { notImplemented, notImplementedAsync } from "../../_internal/utils.ts";
 import type dns from "node:dns/promises";
-import * as constants from "../internal/dns/constants";
-export * from "../internal/dns/constants";
+import * as constants from "../internal/dns/constants.ts";
+export * from "../internal/dns/constants.ts";
 
 export const Resolver: typeof dns.Resolver =
   mock.__createMock__("dns.Resolver");
diff --git a/src/runtime/node/domain.ts b/src/runtime/node/domain.ts
index efc677d9..2c86e1ff 100644
--- a/src/runtime/node/domain.ts
+++ b/src/runtime/node/domain.ts
@@ -1,7 +1,7 @@
 import type domain from "node:domain";
-import { Domain } from "./internal/domain/domain";
+import { Domain } from "./internal/domain/domain.ts";
 
-export { Domain } from "./internal/domain/domain";
+export { Domain } from "./internal/domain/domain.ts";
 
 export const create: typeof domain.create = function () {
   return new Domain();
diff --git a/src/runtime/node/events.ts b/src/runtime/node/events.ts
index 32abf20f..bfe864ef 100644
--- a/src/runtime/node/events.ts
+++ b/src/runtime/node/events.ts
@@ -1,7 +1,7 @@
 // https://nodejs.org/api/events.html
 import type nodeEvents from "node:events";
 
-import { _EventEmitter } from "./internal/events/events";
+import { _EventEmitter } from "./internal/events/events.ts";
 
 export {
   _EventEmitter as EventEmitter,
@@ -11,7 +11,7 @@ export {
   getMaxListeners,
   on,
   once,
-} from "./internal/events/events";
+} from "./internal/events/events.ts";
 
 export const usingDomains = _EventEmitter.usingDomains;
 export const captureRejectionSymbol = _EventEmitter.captureRejectionSymbol;
diff --git a/src/runtime/node/fs.ts b/src/runtime/node/fs.ts
index 4d1a5ee4..ff499216 100644
--- a/src/runtime/node/fs.ts
+++ b/src/runtime/node/fs.ts
@@ -1,15 +1,15 @@
 // https://nodejs.org/api/fs.html
 import type nodeFS from "node:fs";
 
-import * as _classes from "./internal/fs/classes";
-import * as _constants from "./internal/fs/constants";
-import * as _fs from "./internal/fs/fs";
+import * as _classes from "./internal/fs/classes.ts";
+import * as _constants from "./internal/fs/constants.ts";
+import * as _fs from "./internal/fs/fs.ts";
 
-import * as _promises from "./internal/fs/promises";
+import * as _promises from "./internal/fs/promises.ts";
 
-export * from "./internal/fs/classes";
-export * from "./internal/fs/constants";
-export * from "./internal/fs/fs";
+export * from "./internal/fs/classes.ts";
+export * from "./internal/fs/constants.ts";
+export * from "./internal/fs/fs.ts";
 
 export const promises = _promises;
 
diff --git a/src/runtime/node/fs/promises.ts b/src/runtime/node/fs/promises.ts
index 04d53447..d546ebf2 100644
--- a/src/runtime/node/fs/promises.ts
+++ b/src/runtime/node/fs/promises.ts
@@ -1,8 +1,8 @@
 import type fsp from "node:fs/promises";
 
-import * as _promises from "../internal/fs/promises";
+import * as _promises from "../internal/fs/promises.ts";
 
-export * from "../internal/fs/promises";
+export * from "../internal/fs/promises.ts";
 
 export default <typeof fsp>{
   ..._promises,
diff --git a/src/runtime/node/http.ts b/src/runtime/node/http.ts
index a9582a3e..9a86464a 100644
--- a/src/runtime/node/http.ts
+++ b/src/runtime/node/http.ts
@@ -1,14 +1,14 @@
 // https://nodejs.org/api/http.html
 import type http from "node:http";
-import { notImplemented, notImplementedClass } from "../_internal/utils";
-import mock from "../mock/proxy";
-import * as consts from "./internal/http/consts";
-import { IncomingMessage } from "./internal/http/request";
-import { ServerResponse } from "./internal/http/response";
+import { notImplemented, notImplementedClass } from "../_internal/utils.ts";
+import mock from "../mock/proxy.ts";
+import * as consts from "./internal/http/consts.ts";
+import { IncomingMessage } from "./internal/http/request.ts";
+import { ServerResponse } from "./internal/http/response.ts";
 
-export * from "./internal/http/consts";
-export * from "./internal/http/request";
-export * from "./internal/http/response";
+export * from "./internal/http/consts.ts";
+export * from "./internal/http/request.ts";
+export * from "./internal/http/response.ts";
 
 export const createServer =
   /*@__PURE__*/ notImplemented<typeof http.createServer>("http.createServer");
diff --git a/src/runtime/node/http2.ts b/src/runtime/node/http2.ts
index 53a9ca34..0d721c88 100644
--- a/src/runtime/node/http2.ts
+++ b/src/runtime/node/http2.ts
@@ -1,9 +1,9 @@
-import mock from "../mock/proxy";
+import mock from "../mock/proxy.ts";
 import type http2 from "node:http2";
-import { notImplemented } from "../_internal/utils";
-import { constants } from "./internal/http2/constants";
+import { notImplemented } from "../_internal/utils.ts";
+import { constants } from "./internal/http2/constants.ts";
 
-export { constants } from "./internal/http2/constants";
+export { constants } from "./internal/http2/constants.ts";
 
 export const createSecureServer = /*@__PURE__*/ notImplemented<
   typeof http2.createSecureServer
diff --git a/src/runtime/node/https.ts b/src/runtime/node/https.ts
index 9b202ad5..84dafa96 100644
--- a/src/runtime/node/https.ts
+++ b/src/runtime/node/https.ts
@@ -1,7 +1,7 @@
 // https://nodejs.org/api/https.html
 import type nodeHttps from "node:https";
-import { notImplemented, notImplementedClass } from "../_internal/utils";
-import mock from "../mock/proxy";
+import { notImplemented, notImplementedClass } from "../_internal/utils.ts";
+import mock from "../mock/proxy.ts";
 
 export const Server: typeof nodeHttps.Server =
   /*@__PURE__*/ notImplementedClass("https.Server");
diff --git a/src/runtime/node/inspector.ts b/src/runtime/node/inspector.ts
index 5c234d2e..e33a7d59 100644
--- a/src/runtime/node/inspector.ts
+++ b/src/runtime/node/inspector.ts
@@ -1,6 +1,6 @@
 // https://nodejs.org/api/inspector.html
-import noop from "../mock/noop";
-import mock from "../mock/proxy";
+import noop from "../mock/noop.ts";
+import mock from "../mock/proxy.ts";
 import type inspector from "node:inspector";
 
 export const close: typeof inspector.close = noop;
diff --git a/src/runtime/node/internal/async_hooks/async-resource.ts b/src/runtime/node/internal/async_hooks/async-resource.ts
index f421e9d9..0770d11d 100644
--- a/src/runtime/node/internal/async_hooks/async-resource.ts
+++ b/src/runtime/node/internal/async_hooks/async-resource.ts
@@ -1,5 +1,5 @@
 import type asyncHooks from "node:async_hooks";
-import { executionAsyncId } from "./async-hook";
+import { executionAsyncId } from "./async-hook.ts";
 
 // https://nodejs.org/api/async_context.html#class-asyncresource
 
diff --git a/src/runtime/node/internal/buffer/buffer.ts b/src/runtime/node/internal/buffer/buffer.ts
index ed163087..0a8d2bad 100644
--- a/src/runtime/node/internal/buffer/buffer.ts
+++ b/src/runtime/node/internal/buffer/buffer.ts
@@ -8,8 +8,8 @@
  * @license  MIT
  */
 
-import * as base64 from "./base64";
-import * as ieee754 from "./ieee754";
+import * as base64 from "./base64.ts";
+import * as ieee754 from "./ieee754.ts";
 
 const customInspectSymbol =
   typeof Symbol === "function" && typeof Symbol["for"] === "function"
diff --git a/src/runtime/node/internal/crypto/node.ts b/src/runtime/node/internal/crypto/node.ts
index 7850979c..8d6a2616 100644
--- a/src/runtime/node/internal/crypto/node.ts
+++ b/src/runtime/node/internal/crypto/node.ts
@@ -1,7 +1,10 @@
 import type nodeCrypto from "node:crypto";
 
-import { notImplemented, notImplementedClass } from "../../../_internal/utils";
-import { getRandomValues } from "./web";
+import {
+  notImplemented,
+  notImplementedClass,
+} from "../../../_internal/utils.ts";
+import { getRandomValues } from "./web.ts";
 
 // limit of Crypto.getRandomValues()
 // https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues
diff --git a/src/runtime/node/internal/diagnostics_channel/channel.ts b/src/runtime/node/internal/diagnostics_channel/channel.ts
index 4b974241..2f273ba5 100644
--- a/src/runtime/node/internal/diagnostics_channel/channel.ts
+++ b/src/runtime/node/internal/diagnostics_channel/channel.ts
@@ -1,4 +1,4 @@
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 import type diagnostics_channel from "node:diagnostics_channel";
 
 const channels: Record<string | symbol, diagnostics_channel.Channel> = {};
diff --git a/src/runtime/node/internal/diagnostics_channel/tracing-channel.ts b/src/runtime/node/internal/diagnostics_channel/tracing-channel.ts
index b3adb210..839aadea 100644
--- a/src/runtime/node/internal/diagnostics_channel/tracing-channel.ts
+++ b/src/runtime/node/internal/diagnostics_channel/tracing-channel.ts
@@ -1,6 +1,6 @@
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 import type diagnostics_channel from "node:diagnostics_channel";
-import { Channel } from "./channel";
+import { Channel } from "./channel.ts";
 
 export class TracingChannel<
   StoreType = unknown,
diff --git a/src/runtime/node/internal/domain/domain.ts b/src/runtime/node/internal/domain/domain.ts
index 32ec2a7d..04fff3d4 100644
--- a/src/runtime/node/internal/domain/domain.ts
+++ b/src/runtime/node/internal/domain/domain.ts
@@ -1,4 +1,4 @@
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 import { EventEmitter } from "node:events";
 import type domain from "node:domain";
 
diff --git a/src/runtime/node/internal/fs/classes.ts b/src/runtime/node/internal/fs/classes.ts
index 172b1bf6..0fa6d8ba 100644
--- a/src/runtime/node/internal/fs/classes.ts
+++ b/src/runtime/node/internal/fs/classes.ts
@@ -1,5 +1,5 @@
 import type fs from "node:fs";
-import mock from "../../../mock/proxy";
+import mock from "../../../mock/proxy.ts";
 
 export const Dir: typeof fs.Dir = mock.__createMock__("fs.Dir");
 
diff --git a/src/runtime/node/internal/fs/fs.ts b/src/runtime/node/internal/fs/fs.ts
index d08300fd..195d37f5 100644
--- a/src/runtime/node/internal/fs/fs.ts
+++ b/src/runtime/node/internal/fs/fs.ts
@@ -1,6 +1,9 @@
 import type fs from "node:fs";
-import { notImplemented, notImplementedAsync } from "../../../_internal/utils";
-import * as fsp from "./promises";
+import {
+  notImplemented,
+  notImplementedAsync,
+} from "../../../_internal/utils.ts";
+import * as fsp from "./promises.ts";
 
 function callbackify(fn: (...args: any[]) => Promise<any>) {
   const fnc = function (...args: any[]) {
diff --git a/src/runtime/node/internal/fs/promises.ts b/src/runtime/node/internal/fs/promises.ts
index 41a42a98..2238b9c4 100644
--- a/src/runtime/node/internal/fs/promises.ts
+++ b/src/runtime/node/internal/fs/promises.ts
@@ -1,7 +1,7 @@
 import type fsp from "node:fs/promises";
-import { notImplemented } from "../../../_internal/utils";
+import { notImplemented } from "../../../_internal/utils.ts";
 
-export { constants } from "./constants";
+export { constants } from "./constants.ts";
 
 export const access =
   /*@__PURE__*/ notImplemented<typeof fsp.access>("fs.access");
diff --git a/src/runtime/node/internal/http/request.ts b/src/runtime/node/internal/http/request.ts
index 92d84474..c5081fe5 100644
--- a/src/runtime/node/internal/http/request.ts
+++ b/src/runtime/node/internal/http/request.ts
@@ -1,7 +1,6 @@
 import type http from "node:http";
 import { Socket } from "node:net";
-// TODO: https://github.com/unjs/unenv/issues/365
-import { Readable } from "unenv/node/stream";
+import { Readable } from "node:stream";
 import { rawHeaders } from "../../../_internal/utils";
 
 // Docs: https://nodejs.org/api/http.html#http_class_http_incomingmessage
diff --git a/src/runtime/node/internal/http/response.ts b/src/runtime/node/internal/http/response.ts
index 47b141ab..b7c4601a 100644
--- a/src/runtime/node/internal/http/response.ts
+++ b/src/runtime/node/internal/http/response.ts
@@ -1,8 +1,7 @@
 import type http from "node:http";
 import type { Socket } from "node:net";
-import { Callback } from "../../../_internal/types";
-// TODO: https://github.com/unjs/unenv/issues/365
-import { Writable } from "unenv/node/stream";
+import { Callback } from "../../../_internal/types.ts";
+import { Writable } from "node:stream";
 
 // Docs: https://nodejs.org/api/http.html#http_class_http_serverresponse
 // Implementation: https://github.com/nodejs/node/blob/master/lib/_http_outgoing.js
diff --git a/src/runtime/node/internal/net/server.ts b/src/runtime/node/internal/net/server.ts
index 79af7b80..7b655c4e 100644
--- a/src/runtime/node/internal/net/server.ts
+++ b/src/runtime/node/internal/net/server.ts
@@ -1,5 +1,5 @@
 import type * as net from "node:net";
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 import { EventEmitter } from "node:events";
 
 // Docs: https://nodejs.org/api/net.html#net_class_net_server
diff --git a/src/runtime/node/internal/net/socket.ts b/src/runtime/node/internal/net/socket.ts
index 614b9bcd..94db45e4 100644
--- a/src/runtime/node/internal/net/socket.ts
+++ b/src/runtime/node/internal/net/socket.ts
@@ -1,7 +1,7 @@
 import type * as net from "node:net";
-import { Callback, BufferEncoding } from "../../../_internal/types";
+import { Callback, BufferEncoding } from "../../../_internal/types.ts";
 // Relative stream import required, see https://github.com/unjs/unenv/issues/353
-import { Duplex } from "../stream/duplex";
+import { Duplex } from "../stream/duplex.ts";
 
 // Docs: https://nodejs.org/api/net.html#net_class_net_socket
 export class Socket extends Duplex implements net.Socket {
diff --git a/src/runtime/node/internal/os/constants.ts b/src/runtime/node/internal/os/constants.ts
index 8b95f62a..cf587154 100644
--- a/src/runtime/node/internal/os/constants.ts
+++ b/src/runtime/node/internal/os/constants.ts
@@ -1,5 +1,5 @@
 import type os from "node:os";
-import osConstants from "../constants/os";
+import osConstants from "../constants/os.ts";
 
 export const constants: typeof os.constants = {
   ...osConstants,
diff --git a/src/runtime/node/internal/perf_hooks/histogram.ts b/src/runtime/node/internal/perf_hooks/histogram.ts
index fc1ff76f..366eac1d 100644
--- a/src/runtime/node/internal/perf_hooks/histogram.ts
+++ b/src/runtime/node/internal/perf_hooks/histogram.ts
@@ -1,5 +1,5 @@
 import type perf_hooks from "node:perf_hooks";
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 
 class Histogram implements perf_hooks.Histogram {
   min = 9_223_372_036_854_776_000;
diff --git a/src/runtime/node/internal/perf_hooks/performance.ts b/src/runtime/node/internal/perf_hooks/performance.ts
index 0557015f..e8802b70 100644
--- a/src/runtime/node/internal/perf_hooks/performance.ts
+++ b/src/runtime/node/internal/perf_hooks/performance.ts
@@ -1,5 +1,5 @@
 import type perf_hooks from "node:perf_hooks";
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 import {
   _Performance,
   _PerformanceMark,
@@ -7,7 +7,7 @@ import {
   _PerformanceObserver,
   _PerformanceObserverEntryList,
   _PerformanceResourceTiming,
-} from "../../../web/performance/index";
+} from "../../../web/performance/index.ts";
 
 // Non modified APIs
 export {
@@ -15,7 +15,7 @@ export {
   PerformanceObserverEntryList,
   PerformanceEntry,
   PerformanceMeasure,
-} from "../../../web/performance/index";
+} from "../../../web/performance/index.ts";
 
 const nodeTiming = {
   name: "node",
diff --git a/src/runtime/node/internal/process/process.ts b/src/runtime/node/internal/process/process.ts
index 488eae43..1fd3b371 100644
--- a/src/runtime/node/internal/process/process.ts
+++ b/src/runtime/node/internal/process/process.ts
@@ -1,14 +1,14 @@
 // Source: https://github.com/defunctzombie/node-process/blob/77caa43cdaee4ea710aa14d11cea1705293c0ef3/browser.js
 import type nodeProcess from "node:process";
 import { ReadStream, WriteStream } from "node:tty";
-import empty from "../../../mock/empty";
-import { notImplemented } from "../../../_internal/utils";
-import { env } from "./env";
-import { hrtime, nextTick } from "./time";
+import empty from "../../../mock/empty.ts";
+import { notImplemented } from "../../../_internal/utils.ts";
+import { env } from "./env.ts";
+import { hrtime, nextTick } from "./time.ts";
 
-export { hrtime, nextTick } from "./time";
+export { hrtime, nextTick } from "./time.ts";
 
-export { env } from "./env";
+export { env } from "./env.ts";
 
 type Process = NodeJS.Process;
 
diff --git a/src/runtime/node/internal/readline/promises/interface.ts b/src/runtime/node/internal/readline/promises/interface.ts
index 85cbb6ff..d03cdc2a 100644
--- a/src/runtime/node/internal/readline/promises/interface.ts
+++ b/src/runtime/node/internal/readline/promises/interface.ts
@@ -1,6 +1,6 @@
 import type readline from "node:readline/promises";
 import type { Abortable } from "node:events";
-import { Interface as _Interface } from "../interface";
+import { Interface as _Interface } from "../interface.ts";
 
 export class Interface extends _Interface implements readline.Interface {
   question(query: string): Promise<string>;
diff --git a/src/runtime/node/internal/stream/duplex.ts b/src/runtime/node/internal/stream/duplex.ts
index 87ad0647..decfa981 100644
--- a/src/runtime/node/internal/stream/duplex.ts
+++ b/src/runtime/node/internal/stream/duplex.ts
@@ -1,7 +1,7 @@
 import type * as stream from "node:stream";
-import { mergeFns } from "../../../_internal/utils";
-import { Readable } from "./readable";
-import { Writable } from "./writable";
+import { mergeFns } from "../../../_internal/utils.ts";
+import { Readable } from "./readable.ts";
+import { Writable } from "./writable.ts";
 
 // Docs: https://nodejs.org/api/stream.html#stream_duplex_and_transform_streams
 // Implementation: https://github.com/nodejs/node/blob/master/lib/internal/streams/duplex.js
diff --git a/src/runtime/node/internal/stream/readable.ts b/src/runtime/node/internal/stream/readable.ts
index b06216f1..48aba4ea 100644
--- a/src/runtime/node/internal/stream/readable.ts
+++ b/src/runtime/node/internal/stream/readable.ts
@@ -1,6 +1,6 @@
 import type * as stream from "node:stream";
-import type { BufferEncoding, Callback } from "../../../_internal/types";
-import { createNotImplementedError } from "../../../_internal/utils";
+import type { BufferEncoding, Callback } from "../../../_internal/types.ts";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 import { EventEmitter } from "node:events";
 
 // Docs: https://nodejs.org/api/stream.html#stream_readable_streams
diff --git a/src/runtime/node/internal/stream/transform.ts b/src/runtime/node/internal/stream/transform.ts
index b6fecb15..c74ecb29 100644
--- a/src/runtime/node/internal/stream/transform.ts
+++ b/src/runtime/node/internal/stream/transform.ts
@@ -1,5 +1,5 @@
 import type * as stream from "node:stream";
-import { Duplex } from "./duplex";
+import { Duplex } from "./duplex.ts";
 
 // Docs: https://nodejs.org/api/stream.html#stream_duplex_and_transform_streams
 // Implementation: https://github.com/nodejs/node/blob/master/lib/internal/streams/transform.js
diff --git a/src/runtime/node/internal/stream/writable.ts b/src/runtime/node/internal/stream/writable.ts
index bb48e6a8..7e382173 100644
--- a/src/runtime/node/internal/stream/writable.ts
+++ b/src/runtime/node/internal/stream/writable.ts
@@ -1,5 +1,5 @@
 import type * as stream from "node:stream";
-import type { BufferEncoding, Callback } from "../../../_internal/types";
+import type { BufferEncoding, Callback } from "../../../_internal/types.ts";
 
 import { EventEmitter } from "node:events";
 
diff --git a/src/runtime/node/internal/timers/set-immediate.ts b/src/runtime/node/internal/timers/set-immediate.ts
index 7db2eb1c..a255f1b5 100644
--- a/src/runtime/node/internal/timers/set-immediate.ts
+++ b/src/runtime/node/internal/timers/set-immediate.ts
@@ -1,4 +1,4 @@
-import { Immediate } from "./immediate";
+import { Immediate } from "./immediate.ts";
 
 export function setImmediateFallbackPromises<T = void>(value?: T): Promise<T> {
   return new Promise((res) => {
diff --git a/src/runtime/node/internal/timers/set-interval.ts b/src/runtime/node/internal/timers/set-interval.ts
index 1cf4ef24..ddfbe35d 100644
--- a/src/runtime/node/internal/timers/set-interval.ts
+++ b/src/runtime/node/internal/timers/set-interval.ts
@@ -1,4 +1,4 @@
-import { Timeout } from "./timeout";
+import { Timeout } from "./timeout.ts";
 
 export async function* setIntervalFallbackPromises<T = void>(
   delay?: number,
diff --git a/src/runtime/node/internal/timers/set-timeout.ts b/src/runtime/node/internal/timers/set-timeout.ts
index 3f146375..d0aadae1 100644
--- a/src/runtime/node/internal/timers/set-timeout.ts
+++ b/src/runtime/node/internal/timers/set-timeout.ts
@@ -1,5 +1,5 @@
 import type nodeTimers from "node:timers";
-import { Timeout } from "./timeout";
+import { Timeout } from "./timeout.ts";
 
 export function setTimeoutFallbackPromises<T = void>(
   delay?: number,
diff --git a/src/runtime/node/internal/tls/server.ts b/src/runtime/node/internal/tls/server.ts
index 273fe279..68f81d99 100644
--- a/src/runtime/node/internal/tls/server.ts
+++ b/src/runtime/node/internal/tls/server.ts
@@ -1,5 +1,5 @@
 import type tls from "node:tls";
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 import { Server as _Server } from "node:net";
 
 export class Server extends _Server implements tls.Server {
diff --git a/src/runtime/node/internal/tls/tls-socket.ts b/src/runtime/node/internal/tls/tls-socket.ts
index 751e65b0..4373edaf 100644
--- a/src/runtime/node/internal/tls/tls-socket.ts
+++ b/src/runtime/node/internal/tls/tls-socket.ts
@@ -1,6 +1,6 @@
 import type tls from "node:tls";
 import { Socket } from "node:net";
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 
 export class TLSSocket extends Socket implements tls.TLSSocket {
   authorized = false;
diff --git a/src/runtime/node/internal/url/url.ts b/src/runtime/node/internal/url/url.ts
index c6ee2c65..6fd4ef61 100644
--- a/src/runtime/node/internal/url/url.ts
+++ b/src/runtime/node/internal/url/url.ts
@@ -2,14 +2,14 @@
 
 import path from "node:path";
 
-import * as punnycode from "../../punycode";
+import * as punnycode from "../../punycode.ts";
 
 import {
   CHAR_FORWARD_SLASH,
   CHAR_BACKWARD_SLASH,
   CHAR_LOWERCASE_A,
   CHAR_LOWERCASE_Z,
-} from "./constants";
+} from "./constants.ts";
 
 import {
   ERR_INVALID_ARG_TYPE,
@@ -17,7 +17,7 @@ import {
   ERR_INVALID_URL_SCHEME,
   ERR_INVALID_FILE_URL_PATH,
   ERR_INVALID_FILE_URL_HOST,
-} from "./errors";
+} from "./errors.ts";
 
 // Protocols that can allow "unsafe" and "unwise" chars.
 export const unsafeProtocol = new Set(["javascript", "javascript:"]);
diff --git a/src/runtime/node/internal/util/types.ts b/src/runtime/node/internal/util/types.ts
index f923a319..a5dad552 100644
--- a/src/runtime/node/internal/util/types.ts
+++ b/src/runtime/node/internal/util/types.ts
@@ -1,5 +1,5 @@
 import type utilTypes from "node:util/types";
-import { notImplemented } from "../../../_internal/utils";
+import { notImplemented } from "../../../_internal/utils.ts";
 
 export const isExternal: typeof utilTypes.isExternal = (_obj) => false;
 
diff --git a/src/runtime/node/internal/vm/script.ts b/src/runtime/node/internal/vm/script.ts
index c50f5496..3dcb9d7c 100644
--- a/src/runtime/node/internal/vm/script.ts
+++ b/src/runtime/node/internal/vm/script.ts
@@ -1,5 +1,5 @@
 import type vm from "node:vm";
-import { createNotImplementedError } from "../../../_internal/utils";
+import { createNotImplementedError } from "../../../_internal/utils.ts";
 
 export class Script implements vm.Script {
   runInContext(
diff --git a/src/runtime/node/internal/worker_threads/message-channel.ts b/src/runtime/node/internal/worker_threads/message-channel.ts
index 4d3d9eb6..67686812 100644
--- a/src/runtime/node/internal/worker_threads/message-channel.ts
+++ b/src/runtime/node/internal/worker_threads/message-channel.ts
@@ -1,4 +1,4 @@
-import { MessagePort } from "./message-port";
+import { MessagePort } from "./message-port.ts";
 import type worker_threads from "node:worker_threads";
 
 export class MessageChannel implements worker_threads.MessageChannel {
diff --git a/src/runtime/node/internal/zlib/formats/_shared.ts b/src/runtime/node/internal/zlib/formats/_shared.ts
index 826e126a..440dcb70 100644
--- a/src/runtime/node/internal/zlib/formats/_shared.ts
+++ b/src/runtime/node/internal/zlib/formats/_shared.ts
@@ -1,6 +1,6 @@
 import type zlib from "node:zlib";
 import { Transform, type TransformOptions } from "node:stream";
-import { createNotImplementedError } from "../../../../_internal/utils";
+import { createNotImplementedError } from "../../../../_internal/utils.ts";
 
 // Compression
 
diff --git a/src/runtime/node/internal/zlib/formats/brotli.ts b/src/runtime/node/internal/zlib/formats/brotli.ts
index 0a6aa789..37ab5542 100644
--- a/src/runtime/node/internal/zlib/formats/brotli.ts
+++ b/src/runtime/node/internal/zlib/formats/brotli.ts
@@ -1,10 +1,10 @@
 import type zlib from "node:zlib";
-import { notImplemented } from "../../../../_internal/utils";
+import { notImplemented } from "../../../../_internal/utils.ts";
 import {
   ZlibCompress,
   ZLibDecompress,
   notImplementedCompress,
-} from "./_shared";
+} from "./_shared.ts";
 
 // Brotli Compression
 
diff --git a/src/runtime/node/internal/zlib/formats/deflate.ts b/src/runtime/node/internal/zlib/formats/deflate.ts
index 5e238cdb..96fb2a57 100644
--- a/src/runtime/node/internal/zlib/formats/deflate.ts
+++ b/src/runtime/node/internal/zlib/formats/deflate.ts
@@ -1,11 +1,11 @@
 import type zlib from "node:zlib";
-import { createNotImplementedError } from "../../../../_internal/utils";
-import { notImplemented } from "../../../../_internal/utils";
+import { createNotImplementedError } from "../../../../_internal/utils.ts";
+import { notImplemented } from "../../../../_internal/utils.ts";
 import {
   ZlibCompress,
   ZLibDecompress,
   notImplementedCompress,
-} from "./_shared";
+} from "./_shared.ts";
 
 // Deflate Compression
 
diff --git a/src/runtime/node/internal/zlib/formats/gzip.ts b/src/runtime/node/internal/zlib/formats/gzip.ts
index 2cb6b689..91b146de 100644
--- a/src/runtime/node/internal/zlib/formats/gzip.ts
+++ b/src/runtime/node/internal/zlib/formats/gzip.ts
@@ -1,10 +1,10 @@
 import type zlib from "node:zlib";
-import { notImplemented } from "../../../../_internal/utils";
+import { notImplemented } from "../../../../_internal/utils.ts";
 import {
   ZlibCompress,
   ZLibDecompress,
   notImplementedCompress,
-} from "./_shared";
+} from "./_shared.ts";
 
 // Gzip Compression
 
diff --git a/src/runtime/node/internal/zlib/formats/zip.ts b/src/runtime/node/internal/zlib/formats/zip.ts
index faf92451..b091ed2f 100644
--- a/src/runtime/node/internal/zlib/formats/zip.ts
+++ b/src/runtime/node/internal/zlib/formats/zip.ts
@@ -1,6 +1,6 @@
 import type zlib from "node:zlib";
-import { notImplemented } from "../../../../_internal/utils";
-import { ZlibCompress } from "./_shared";
+import { notImplemented } from "../../../../_internal/utils.ts";
+import { ZlibCompress } from "./_shared.ts";
 
 // Zip Decompression
 
diff --git a/src/runtime/node/module.ts b/src/runtime/node/module.ts
index a74fb55b..d814d858 100644
--- a/src/runtime/node/module.ts
+++ b/src/runtime/node/module.ts
@@ -1,6 +1,6 @@
 // https://nodejs.org/api/module.html
 import type nodeModule from "node:module";
-import { notImplemented, notImplementedClass } from "../_internal/utils";
+import { notImplemented, notImplementedClass } from "../_internal/utils.ts";
 
 export const _cache = Object.create(null);
 
diff --git a/src/runtime/node/net.ts b/src/runtime/node/net.ts
index 77e72597..f1bc5629 100644
--- a/src/runtime/node/net.ts
+++ b/src/runtime/node/net.ts
@@ -1,15 +1,19 @@
 // https://nodejs.org/api/net.html
 import type net from "node:net";
 
-import { notImplemented, notImplementedClass } from "../_internal/utils";
+import { notImplemented, notImplementedClass } from "../_internal/utils.ts";
 
-import { Socket, SocketAddress } from "./internal/net/socket";
-import { Server } from "./internal/net/server";
+import { Socket, SocketAddress } from "./internal/net/socket.ts";
+import { Server } from "./internal/net/server.ts";
 
-export { Server } from "./internal/net/server";
+export { Server } from "./internal/net/server.ts";
 
 // require('node:net').Socket === require('node:net').Stream
-export { Socket, SocketAddress, Socket as Stream } from "./internal/net/socket";
+export {
+  Socket,
+  SocketAddress,
+  Socket as Stream,
+} from "./internal/net/socket.ts";
 
 export const createServer = /*@__PURE__*/ notImplemented(
   "net.createServer",
diff --git a/src/runtime/node/os.ts b/src/runtime/node/os.ts
index b4986dac..db07a226 100644
--- a/src/runtime/node/os.ts
+++ b/src/runtime/node/os.ts
@@ -1,8 +1,8 @@
 import type os from "node:os";
-import { notImplemented } from "../_internal/utils";
-import { constants } from "./internal/os/constants";
+import { notImplemented } from "../_internal/utils.ts";
+import { constants } from "./internal/os/constants.ts";
 
-export { constants } from "./internal/os/constants";
+export { constants } from "./internal/os/constants.ts";
 
 const NUM_CPUS = 8;
 
diff --git a/src/runtime/node/path.ts b/src/runtime/node/path.ts
index e0fc12bf..1af11862 100644
--- a/src/runtime/node/path.ts
+++ b/src/runtime/node/path.ts
@@ -2,7 +2,7 @@
 // https://github.com/unjs/pathe
 import type nodePath from "node:path";
 
-import { notImplemented } from "../_internal/utils";
+import { notImplemented } from "../_internal/utils.ts";
 
 import * as _path from "pathe";
 export * from "pathe";
diff --git a/src/runtime/node/path/posix.ts b/src/runtime/node/path/posix.ts
index ebc8053e..f6e24a2c 100644
--- a/src/runtime/node/path/posix.ts
+++ b/src/runtime/node/path/posix.ts
@@ -1,2 +1,2 @@
-export * from "../path";
-export { default } from "../path";
+export * from "../path.ts";
+export { default } from "../path.ts";
diff --git a/src/runtime/node/path/win32.ts b/src/runtime/node/path/win32.ts
index ebc8053e..f6e24a2c 100644
--- a/src/runtime/node/path/win32.ts
+++ b/src/runtime/node/path/win32.ts
@@ -1,2 +1,2 @@
-export * from "../path";
-export { default } from "../path";
+export * from "../path.ts";
+export { default } from "../path.ts";
diff --git a/src/runtime/node/perf_hooks.ts b/src/runtime/node/perf_hooks.ts
index 1acb1188..08b002a5 100644
--- a/src/runtime/node/perf_hooks.ts
+++ b/src/runtime/node/perf_hooks.ts
@@ -2,8 +2,8 @@ import type perf_hooks from "node:perf_hooks";
 import {
   IntervalHistogram,
   RecordableHistogram,
-} from "./internal/perf_hooks/histogram";
-import { constants } from "./internal/perf_hooks/constants";
+} from "./internal/perf_hooks/histogram.ts";
+import { constants } from "./internal/perf_hooks/constants.ts";
 import {
   performance,
   Performance,
@@ -13,10 +13,10 @@ import {
   PerformanceObserverEntryList,
   PerformanceObserver,
   PerformanceResourceTiming,
-} from "./internal/perf_hooks/performance";
-export { constants } from "./internal/perf_hooks/constants";
+} from "./internal/perf_hooks/performance.ts";
+export { constants } from "./internal/perf_hooks/constants.ts";
 
-export * from "./internal/perf_hooks/performance";
+export * from "./internal/perf_hooks/performance.ts";
 
 export const monitorEventLoopDelay: typeof perf_hooks.monitorEventLoopDelay =
   function (_options) {
diff --git a/src/runtime/node/process.ts b/src/runtime/node/process.ts
index 700cc62f..6c1d1521 100644
--- a/src/runtime/node/process.ts
+++ b/src/runtime/node/process.ts
@@ -1,8 +1,8 @@
 // https://nodejs.org/api/process.html
 import type nodeProcess from "node:process";
 
-import { process as unenvProcess } from "./internal/process/process";
+import { process as unenvProcess } from "./internal/process/process.ts";
 
-export * from "./internal/process/process";
+export * from "./internal/process/process.ts";
 
 export default unenvProcess as unknown as typeof nodeProcess;
diff --git a/src/runtime/node/punycode.ts b/src/runtime/node/punycode.ts
index 094e7d93..ece73c21 100644
--- a/src/runtime/node/punycode.ts
+++ b/src/runtime/node/punycode.ts
@@ -1,7 +1,7 @@
 import type punycode from "node:punycode";
 
-import _punycode from "./internal/punycode/punycode";
+import _punycode from "./internal/punycode/punycode.ts";
 
-export * from "./internal/punycode/punycode";
+export * from "./internal/punycode/punycode.ts";
 
 export default _punycode satisfies typeof punycode;
diff --git a/src/runtime/node/querystring.ts b/src/runtime/node/querystring.ts
index cf75bb83..f9026ad7 100644
--- a/src/runtime/node/querystring.ts
+++ b/src/runtime/node/querystring.ts
@@ -25,7 +25,7 @@ import {
   encodeStr,
   hexTable,
   isHexTable,
-} from "./internal/querystring/querystring";
+} from "./internal/querystring/querystring.ts";
 
 // prettier-ignore
 const unhexTable = new Int8Array([
diff --git a/src/runtime/node/readline.ts b/src/runtime/node/readline.ts
index ce6765b3..2f006097 100644
--- a/src/runtime/node/readline.ts
+++ b/src/runtime/node/readline.ts
@@ -1,11 +1,11 @@
 // https://nodejs.org/api/readline.html#readlineclearlinestream-dir-callback
 import type readline from "node:readline";
-import noop from "../mock/noop";
-import promises from "./readline/promises";
-import { Interface } from "./internal/readline/interface";
+import noop from "../mock/noop.ts";
+import promises from "./readline/promises.ts";
+import { Interface } from "./internal/readline/interface.ts";
 
-export * as promises from "./readline/promises";
-export { Interface } from "./internal/readline/interface";
+export * as promises from "./readline/promises.ts";
+export { Interface } from "./internal/readline/interface.ts";
 
 export const clearLine: typeof readline.clearLine = () => false;
 export const clearScreenDown: typeof readline.clearScreenDown = () => false;
diff --git a/src/runtime/node/readline/promises.ts b/src/runtime/node/readline/promises.ts
index d8ec5cda..3dead716 100644
--- a/src/runtime/node/readline/promises.ts
+++ b/src/runtime/node/readline/promises.ts
@@ -1,9 +1,9 @@
 import type readline from "node:readline/promises";
-import { Interface } from "../internal/readline/promises/interface";
-import { Readline } from "../internal/readline/promises/readline";
+import { Interface } from "../internal/readline/promises/interface.ts";
+import { Readline } from "../internal/readline/promises/readline.ts";
 
-export { Interface } from "../internal/readline/promises/interface";
-export { Readline } from "../internal/readline/promises/readline";
+export { Interface } from "../internal/readline/promises/interface.ts";
+export { Readline } from "../internal/readline/promises/readline.ts";
 
 export const createInterface: typeof readline.createInterface = () =>
   new Interface();
diff --git a/src/runtime/node/stream.ts b/src/runtime/node/stream.ts
index a36252bc..255cbd7e 100644
--- a/src/runtime/node/stream.ts
+++ b/src/runtime/node/stream.ts
@@ -1,18 +1,18 @@
 // https://nodejs.org/api/stream.html
 import type stream from "node:stream";
-import mock from "../mock/proxy";
-import { notImplemented } from "../_internal/utils";
-import { Readable } from "./internal/stream/readable";
-import { Writable } from "./internal/stream/writable";
-import { Duplex } from "./internal/stream/duplex";
-import { Transform } from "./internal/stream/transform";
+import mock from "../mock/proxy.ts";
+import { notImplemented } from "../_internal/utils.ts";
+import { Readable } from "./internal/stream/readable.ts";
+import { Writable } from "./internal/stream/writable.ts";
+import { Duplex } from "./internal/stream/duplex.ts";
+import { Transform } from "./internal/stream/transform.ts";
 
-import promises from "./stream/promises";
+import promises from "./stream/promises.ts";
 
-export { Readable } from "./internal/stream/readable";
-export { Writable } from "./internal/stream/writable";
-export { Duplex } from "./internal/stream/duplex";
-export { Transform } from "./internal/stream/transform";
+export { Readable } from "./internal/stream/readable.ts";
+export { Writable } from "./internal/stream/writable.ts";
+export { Duplex } from "./internal/stream/duplex.ts";
+export { Transform } from "./internal/stream/transform.ts";
 
 export const Stream: stream.Stream = mock.__createMock__("Stream");
 export const PassThrough: stream.PassThrough =
diff --git a/src/runtime/node/stream/consumers.ts b/src/runtime/node/stream/consumers.ts
index 1c920b17..d247504a 100644
--- a/src/runtime/node/stream/consumers.ts
+++ b/src/runtime/node/stream/consumers.ts
@@ -1,5 +1,5 @@
 import type * as streamConsumers from "node:stream/consumers";
-import { notImplemented } from "../../_internal/utils";
+import { notImplemented } from "../../_internal/utils.ts";
 
 export const arrayBuffer = /*@__PURE__*/ notImplemented(
   "stream.consumers.arrayBuffer",
diff --git a/src/runtime/node/stream/promises.ts b/src/runtime/node/stream/promises.ts
index 8c226e89..394f58a4 100644
--- a/src/runtime/node/stream/promises.ts
+++ b/src/runtime/node/stream/promises.ts
@@ -1,5 +1,5 @@
 import type * as streamPromises from "node:stream/promises";
-import { notImplemented } from "../../_internal/utils";
+import { notImplemented } from "../../_internal/utils.ts";
 
 export const finished = /*@__PURE__*/ notImplemented(
   "stream.promises.finished",
diff --git a/src/runtime/node/stream/web.ts b/src/runtime/node/stream/web.ts
index f6972472..41f5f93a 100644
--- a/src/runtime/node/stream/web.ts
+++ b/src/runtime/node/stream/web.ts
@@ -1,5 +1,5 @@
 import type * as streamWeb from "node:stream/web";
-import { notImplemented } from "../../_internal/utils";
+import { notImplemented } from "../../_internal/utils.ts";
 
 export const ReadableStream =
   globalThis.ReadableStream ||
diff --git a/src/runtime/node/string_decoder.ts b/src/runtime/node/string_decoder.ts
index 62c4ea1a..7c2ce632 100644
--- a/src/runtime/node/string_decoder.ts
+++ b/src/runtime/node/string_decoder.ts
@@ -1,6 +1,6 @@
 // https://nodejs.org/api/string_decoder.html
 import type stringDecoder from "node:string_decoder";
-import { notImplementedClass } from "../_internal/utils";
+import { notImplementedClass } from "../_internal/utils.ts";
 
 export const StringDecoder: typeof stringDecoder.StringDecoder =
   (globalThis as any).StringDecoder ||
diff --git a/src/runtime/node/sys.ts b/src/runtime/node/sys.ts
index dcc0d503..f2c80296 100644
--- a/src/runtime/node/sys.ts
+++ b/src/runtime/node/sys.ts
@@ -1,2 +1,2 @@
-export * from "./util";
-export { default } from "./util";
+export * from "./util.ts";
+export { default } from "./util.ts";
diff --git a/src/runtime/node/timers.ts b/src/runtime/node/timers.ts
index d22a9882..518506a6 100644
--- a/src/runtime/node/timers.ts
+++ b/src/runtime/node/timers.ts
@@ -1,15 +1,15 @@
-import { notImplemented } from "../_internal/utils";
-import noop from "../mock/noop";
+import { notImplemented } from "../_internal/utils.ts";
+import noop from "../mock/noop.ts";
 import type timers from "node:timers";
-import promises from "./timers/promises";
-import { setTimeoutFallback } from "./internal/timers/set-timeout";
+import promises from "./timers/promises.ts";
+import { setTimeoutFallback } from "./internal/timers/set-timeout.ts";
 import {
   setImmediateFallback,
   clearImmediateFallback,
-} from "./internal/timers/set-immediate";
-import { setIntervalFallback } from "./internal/timers/set-interval";
+} from "./internal/timers/set-immediate.ts";
+import { setIntervalFallback } from "./internal/timers/set-interval.ts";
 
-export * as promises from "./timers/promises";
+export * as promises from "./timers/promises.ts";
 
 export const clearImmediate: typeof timers.clearImmediate =
   globalThis.clearImmediate?.bind(globalThis) || clearImmediateFallback;
diff --git a/src/runtime/node/timers/promises.ts b/src/runtime/node/timers/promises.ts
index b8537530..41e1c912 100644
--- a/src/runtime/node/timers/promises.ts
+++ b/src/runtime/node/timers/promises.ts
@@ -1,12 +1,12 @@
 import type timers from "node:timers/promises";
-import { Scheduler } from "../internal/timers/scheduler";
-import { setTimeoutFallbackPromises } from "../internal/timers/set-timeout";
-import { setIntervalFallbackPromises } from "../internal/timers/set-interval";
-import { setImmediateFallbackPromises } from "../internal/timers/set-immediate";
+import { Scheduler } from "../internal/timers/scheduler.ts";
+import { setTimeoutFallbackPromises } from "../internal/timers/set-timeout.ts";
+import { setIntervalFallbackPromises } from "../internal/timers/set-interval.ts";
+import { setImmediateFallbackPromises } from "../internal/timers/set-immediate.ts";
 
-export { setTimeoutFallbackPromises as setTimeout } from "../internal/timers/set-timeout";
-export { setIntervalFallbackPromises as setInterval } from "../internal/timers/set-interval";
-export { setImmediateFallbackPromises as setImmediate } from "../internal/timers/set-immediate";
+export { setTimeoutFallbackPromises as setTimeout } from "../internal/timers/set-timeout.ts";
+export { setIntervalFallbackPromises as setInterval } from "../internal/timers/set-interval.ts";
+export { setImmediateFallbackPromises as setImmediate } from "../internal/timers/set-immediate.ts";
 
 export const scheduler = new Scheduler();
 
diff --git a/src/runtime/node/tls.ts b/src/runtime/node/tls.ts
index f9587b76..56375321 100644
--- a/src/runtime/node/tls.ts
+++ b/src/runtime/node/tls.ts
@@ -1,14 +1,14 @@
 import type tls from "node:tls";
-import { notImplemented } from "../_internal/utils";
-import { TLSSocket } from "./internal/tls/tls-socket";
-import { Server } from "./internal/tls/server";
-import { SecureContext } from "./internal/tls/secure-context";
-import * as constants from "./internal/tls/constants";
+import { notImplemented } from "../_internal/utils.ts";
+import { TLSSocket } from "./internal/tls/tls-socket.ts";
+import { Server } from "./internal/tls/server.ts";
+import { SecureContext } from "./internal/tls/secure-context.ts";
+import * as constants from "./internal/tls/constants.ts";
 
-export * from "./internal/tls/constants";
-export { TLSSocket } from "./internal/tls/tls-socket";
-export { Server } from "./internal/tls/server";
-export { SecureContext } from "./internal/tls/secure-context";
+export * from "./internal/tls/constants.ts";
+export { TLSSocket } from "./internal/tls/tls-socket.ts";
+export { Server } from "./internal/tls/server.ts";
+export { SecureContext } from "./internal/tls/secure-context.ts";
 
 export const connect: typeof tls.connect = function connect() {
   return new TLSSocket();
diff --git a/src/runtime/node/trace_events.ts b/src/runtime/node/trace_events.ts
index 82fc3b34..b0b62c68 100644
--- a/src/runtime/node/trace_events.ts
+++ b/src/runtime/node/trace_events.ts
@@ -1,5 +1,5 @@
 import type trace_events from "node:trace_events";
-import { Tracing } from "./internal/trace_events/tracing";
+import { Tracing } from "./internal/trace_events/tracing.ts";
 
 export const createTracing: typeof trace_events.createTracing = function () {
   return new Tracing();
diff --git a/src/runtime/node/tty.ts b/src/runtime/node/tty.ts
index 9362fbc9..005e9b6c 100644
--- a/src/runtime/node/tty.ts
+++ b/src/runtime/node/tty.ts
@@ -1,9 +1,9 @@
 import type tty from "node:tty";
-import { ReadStream } from "./internal/tty/read-stream";
-import { WriteStream } from "./internal/tty/write-stream";
+import { ReadStream } from "./internal/tty/read-stream.ts";
+import { WriteStream } from "./internal/tty/write-stream.ts";
 
-export { ReadStream } from "./internal/tty/read-stream";
-export { WriteStream } from "./internal/tty/write-stream";
+export { ReadStream } from "./internal/tty/read-stream.ts";
+export { WriteStream } from "./internal/tty/write-stream.ts";
 
 export const isatty: typeof tty.isatty = function () {
   return false;
diff --git a/src/runtime/node/url.ts b/src/runtime/node/url.ts
index be57b0ec..c3038851 100644
--- a/src/runtime/node/url.ts
+++ b/src/runtime/node/url.ts
@@ -25,13 +25,16 @@ import type nodeUrl from "node:url";
 
 import * as querystring from "node:querystring";
 
-import * as punnycode from "./punycode";
+import * as punnycode from "./punycode.ts";
 
-import { encodeStr, hexTable } from "./internal/querystring/querystring";
+import { encodeStr, hexTable } from "./internal/querystring/querystring.ts";
 
-import { spliceOne } from "./internal/url/util";
+import { spliceOne } from "./internal/url/util.ts";
 
-import { ERR_INVALID_ARG_TYPE, ERR_INVALID_URL } from "./internal/url/errors";
+import {
+  ERR_INVALID_ARG_TYPE,
+  ERR_INVALID_URL,
+} from "./internal/url/errors.ts";
 
 import {
   pathToFileURL as _pathToFileURL,
@@ -40,7 +43,7 @@ import {
   hostlessProtocol,
   slashedProtocol,
   urlToHttpOptions,
-} from "./internal/url/url";
+} from "./internal/url/url.ts";
 
 import {
   CHAR_SPACE,
@@ -68,7 +71,7 @@ import {
   CHAR_VERTICAL_LINE,
   CHAR_AT,
   CHAR_COLON,
-} from "./internal/url/constants";
+} from "./internal/url/constants.ts";
 
 class Url implements nodeUrl.Url {
   auth: string | null = null;
diff --git a/src/runtime/node/util.ts b/src/runtime/node/util.ts
index f2644cae..10b87683 100644
--- a/src/runtime/node/util.ts
+++ b/src/runtime/node/util.ts
@@ -1,20 +1,20 @@
 // https://nodejs.org/api/util.html
 import type util from "node:util";
-import { notImplemented } from "../_internal/utils";
-import inherits from "../npm/inherits";
-import * as legacyTypes from "./internal/util/legacy-types";
-import * as logUtils from "./internal/util/log";
-import types from "./util/types";
-import { promisify } from "./internal/util/promisify";
-import * as mime from "./internal/util/mime";
+import { notImplemented } from "../_internal/utils.ts";
+import inherits from "../npm/inherits.ts";
+import * as legacyTypes from "./internal/util/legacy-types.ts";
+import * as logUtils from "./internal/util/log.ts";
+import types from "./util/types.ts";
+import { promisify } from "./internal/util/promisify.ts";
+import * as mime from "./internal/util/mime.ts";
 
-export * from "./internal/util/mime";
-export * from "./internal/util/legacy-types";
-export * from "./internal/util/log";
+export * from "./internal/util/mime.ts";
+export * from "./internal/util/legacy-types.ts";
+export * from "./internal/util/log.ts";
 
-export { default as inherits } from "../npm/inherits";
-export { promisify } from "./internal/util/promisify";
-export { default as types } from "./util/types";
+export { default as inherits } from "../npm/inherits.ts";
+export { promisify } from "./internal/util/promisify.ts";
+export { default as types } from "./util/types.ts";
 
 // @ts-ignore
 export const TextDecoder: typeof util.TextDecoder = globalThis.TextDecoder;
diff --git a/src/runtime/node/util/types.ts b/src/runtime/node/util/types.ts
index 36ec8f27..d57175eb 100644
--- a/src/runtime/node/util/types.ts
+++ b/src/runtime/node/util/types.ts
@@ -1,7 +1,7 @@
 import type utilTypes from "node:util/types";
 
-import * as types from "../internal/util/types";
+import * as types from "../internal/util/types.ts";
 
-export * from "../internal/util/types";
+export * from "../internal/util/types.ts";
 
 export default <typeof utilTypes>types;
diff --git a/src/runtime/node/v8.ts b/src/runtime/node/v8.ts
index 37dafe95..7756e828 100644
--- a/src/runtime/node/v8.ts
+++ b/src/runtime/node/v8.ts
@@ -1,13 +1,19 @@
-import noop from "../mock/noop";
+import noop from "../mock/noop.ts";
 import type v8 from "node:v8";
 import { Readable } from "node:stream";
-import { Deserializer, DefaultDeserializer } from "./internal/v8/deserializer";
-import { Serializer, DefaultSerializer } from "./internal/v8/serializer";
-import { GCProfiler } from "./internal/v8/profiler";
+import {
+  Deserializer,
+  DefaultDeserializer,
+} from "./internal/v8/deserializer.ts";
+import { Serializer, DefaultSerializer } from "./internal/v8/serializer.ts";
+import { GCProfiler } from "./internal/v8/profiler.ts";
 
-export { Deserializer, DefaultDeserializer } from "./internal/v8/deserializer";
-export { Serializer, DefaultSerializer } from "./internal/v8/serializer";
-export { GCProfiler } from "./internal/v8/profiler";
+export {
+  Deserializer,
+  DefaultDeserializer,
+} from "./internal/v8/deserializer.ts";
+export { Serializer, DefaultSerializer } from "./internal/v8/serializer.ts";
+export { GCProfiler } from "./internal/v8/profiler.ts";
 
 const getMockHeapSpaceStats = (name: string) => ({
   space_name: name,
diff --git a/src/runtime/node/vm.ts b/src/runtime/node/vm.ts
index 13b25323..3d84cdb6 100644
--- a/src/runtime/node/vm.ts
+++ b/src/runtime/node/vm.ts
@@ -1,10 +1,10 @@
 import type vm from "node:vm";
-import { notImplemented } from "../_internal/utils";
-import { Script } from "./internal/vm/script";
-import * as constants from "./internal/vm/constants";
+import { notImplemented } from "../_internal/utils.ts";
+import { Script } from "./internal/vm/script.ts";
+import * as constants from "./internal/vm/constants.ts";
 
-export { Script } from "./internal/vm/script";
-export * as constants from "./internal/vm/constants";
+export { Script } from "./internal/vm/script.ts";
+export * as constants from "./internal/vm/constants.ts";
 
 export const compileFunction: typeof vm.compileFunction =
   /*@__PURE__*/ notImplemented("vm.compileFunction");
diff --git a/src/runtime/node/wasi.ts b/src/runtime/node/wasi.ts
index 6bd88c53..03e5ade3 100644
--- a/src/runtime/node/wasi.ts
+++ b/src/runtime/node/wasi.ts
@@ -1,5 +1,5 @@
 import type wasi from "node:wasi";
-import { notImplementedClass } from "../_internal/utils";
+import { notImplementedClass } from "../_internal/utils.ts";
 
 export const WASI: typeof wasi.WASI =
   /*@__PURE__*/ notImplementedClass("wasi.WASI");
diff --git a/src/runtime/node/worker_threads.ts b/src/runtime/node/worker_threads.ts
index 8d758eeb..d42c3cdf 100644
--- a/src/runtime/node/worker_threads.ts
+++ b/src/runtime/node/worker_threads.ts
@@ -1,15 +1,15 @@
 import type worker_threads from "node:worker_threads";
-import { BroadcastChannel } from "./internal/worker_threads/broadcast-channel";
-import { MessageChannel } from "./internal/worker_threads/message-channel";
-import { MessagePort } from "./internal/worker_threads/message-port";
-import { Worker } from "./internal/worker_threads/worker";
+import { BroadcastChannel } from "./internal/worker_threads/broadcast-channel.ts";
+import { MessageChannel } from "./internal/worker_threads/message-channel.ts";
+import { MessagePort } from "./internal/worker_threads/message-port.ts";
+import { Worker } from "./internal/worker_threads/worker.ts";
 import { Serializable } from "node:worker_threads";
-import { notImplemented } from "../_internal/utils";
+import { notImplemented } from "../_internal/utils.ts";
 
-export { BroadcastChannel } from "./internal/worker_threads/broadcast-channel";
-export { MessageChannel } from "./internal/worker_threads/message-channel";
-export { MessagePort } from "./internal/worker_threads/message-port";
-export { Worker } from "./internal/worker_threads/worker";
+export { BroadcastChannel } from "./internal/worker_threads/broadcast-channel.ts";
+export { MessageChannel } from "./internal/worker_threads/message-channel.ts";
+export { MessagePort } from "./internal/worker_threads/message-port.ts";
+export { Worker } from "./internal/worker_threads/worker.ts";
 
 const _environmentData = new Map<string, Serializable>();
 export const getEnvironmentData: typeof worker_threads.getEnvironmentData =
diff --git a/src/runtime/node/zlib.ts b/src/runtime/node/zlib.ts
index 3ea9a2be..c6cd0891 100644
--- a/src/runtime/node/zlib.ts
+++ b/src/runtime/node/zlib.ts
@@ -1,20 +1,20 @@
 import type zlib from "node:zlib";
 
-import { constants } from "./internal/zlib/constants";
-import { codes } from "./internal/zlib/codes";
+import { constants } from "./internal/zlib/constants.ts";
+import { codes } from "./internal/zlib/codes.ts";
 
-import * as _brotli from "./internal/zlib/formats/brotli";
-import * as _deflate from "./internal/zlib/formats/deflate";
-import * as _gzip from "./internal/zlib/formats/gzip";
-import * as _zip from "./internal/zlib/formats/zip";
+import * as _brotli from "./internal/zlib/formats/brotli.ts";
+import * as _deflate from "./internal/zlib/formats/deflate.ts";
+import * as _gzip from "./internal/zlib/formats/gzip.ts";
+import * as _zip from "./internal/zlib/formats/zip.ts";
 
-export { constants } from "./internal/zlib/constants";
-export { codes } from "./internal/zlib/codes";
+export { constants } from "./internal/zlib/constants.ts";
+export { codes } from "./internal/zlib/codes.ts";
 
-export * from "./internal/zlib/formats/brotli";
-export * from "./internal/zlib/formats/deflate";
-export * from "./internal/zlib/formats/gzip";
-export * from "./internal/zlib/formats/zip";
+export * from "./internal/zlib/formats/brotli.ts";
+export * from "./internal/zlib/formats/deflate.ts";
+export * from "./internal/zlib/formats/gzip.ts";
+export * from "./internal/zlib/formats/zip.ts";
 
 // Deprecated constants
 const Z_BINARY: typeof zlib.Z_BINARY = 0;
diff --git a/src/runtime/npm/whatwg-url.ts b/src/runtime/npm/whatwg-url.ts
index 3488f7d8..79b0f695 100644
--- a/src/runtime/npm/whatwg-url.ts
+++ b/src/runtime/npm/whatwg-url.ts
@@ -1,5 +1,5 @@
 // https://www.npmjs.com/package/whatwg-url
-import { notImplemented } from "../_internal/utils";
+import { notImplemented } from "../_internal/utils.ts";
 
 export const URL = globalThis.URL;
 export const URLSearchParams = globalThis.URLSearchParams;
diff --git a/src/runtime/polyfill/global.ts b/src/runtime/polyfill/global.ts
index 86139f54..2274b826 100644
--- a/src/runtime/polyfill/global.ts
+++ b/src/runtime/polyfill/global.ts
@@ -1,4 +1,4 @@
-import _global from "./global-this";
+import _global from "./global-this.ts";
 
 try {
   const _defineOpts: PropertyDescriptor = { enumerable: false, value: _global };
diff --git a/src/runtime/polyfill/performance.ts b/src/runtime/polyfill/performance.ts
index b3b3b0db..9d6304ab 100644
--- a/src/runtime/polyfill/performance.ts
+++ b/src/runtime/polyfill/performance.ts
@@ -7,8 +7,8 @@ import {
   PerformanceObserver,
   PerformanceObserverEntryList,
   PerformanceResourceTiming,
-} from "../web/performance";
-import _global from "./global-this";
+} from "../web/performance/index.ts";
+import _global from "./global-this.ts";
 
 _global.performance = _global.performance || performance;
 _global.Performance = _global.Performance || Performance;
diff --git a/src/runtime/polyfill/process.ts b/src/runtime/polyfill/process.ts
index 3950d8a0..77853702 100644
--- a/src/runtime/polyfill/process.ts
+++ b/src/runtime/polyfill/process.ts
@@ -1,5 +1,5 @@
 import type nodeProcess from "node:process";
-import unenvProcess from "../node/process";
+import unenvProcess from "../node/process.ts";
 
 // use Object.assign to preserve the identity of globalThis.process
 Object.assign(globalThis.process, {
diff --git a/src/runtime/web/performance/_observer.ts b/src/runtime/web/performance/_observer.ts
index 73693f46..af7e9b3c 100644
--- a/src/runtime/web/performance/_observer.ts
+++ b/src/runtime/web/performance/_observer.ts
@@ -1,5 +1,5 @@
-import { createNotImplementedError } from "../../_internal/utils";
-import { _supportedEntryTypes } from "./_entry";
+import { createNotImplementedError } from "../../_internal/utils.ts";
+import { _supportedEntryTypes } from "./_entry.ts";
 
 // https://developer.mozilla.org/en-US/docs/Web/API/PerformanceObserver
 export class _PerformanceObserver implements globalThis.PerformanceObserver {
diff --git a/src/runtime/web/performance/_performance.ts b/src/runtime/web/performance/_performance.ts
index a1cd2491..0f496816 100644
--- a/src/runtime/web/performance/_performance.ts
+++ b/src/runtime/web/performance/_performance.ts
@@ -1,6 +1,6 @@
-import { createNotImplementedError } from "../../_internal/utils";
-import mock from "../../mock/proxy";
-import { _PerformanceMark, _PerformanceMeasure } from "./_entry";
+import { createNotImplementedError } from "../../_internal/utils.ts";
+import mock from "../../mock/proxy.ts";
+import { _PerformanceMark, _PerformanceMeasure } from "./_entry.ts";
 
 const _timeOrigin = Date.now();
 
diff --git a/src/runtime/web/performance/index.ts b/src/runtime/web/performance/index.ts
index 6ec45e1e..cebe12f5 100644
--- a/src/runtime/web/performance/index.ts
+++ b/src/runtime/web/performance/index.ts
@@ -1,13 +1,13 @@
 // https://developer.mozilla.org/en-US/docs/Web/API/Performance_API
 
-export { Performance, _Performance, performance } from "./_performance";
+export { Performance, _Performance, performance } from "./_performance.ts";
 
 export {
   PerformanceObserver,
   _PerformanceObserver,
   PerformanceObserverEntryList,
   _PerformanceObserverEntryList,
-} from "./_observer";
+} from "./_observer.ts";
 
 export {
   PerformanceEntry,
@@ -18,7 +18,7 @@ export {
   _PerformanceMeasure,
   PerformanceResourceTiming,
   _PerformanceResourceTiming,
-} from "./_entry";
+} from "./_entry.ts";
 
 // Not implemented:
 // EventCounts
diff --git a/tsconfig.json b/tsconfig.json
index 21595ec8..ae78a47e 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -7,6 +7,7 @@
     "strict": true,
     "declaration": true,
     "resolveJsonModule": true,
+    "allowImportingTsExtensions": true,
     "isolatedDeclarations": false,
     "types": [
       "node"