diff --git a/packages/frontend/vite.config.ts b/packages/frontend/vite.config.ts
index df3719258..35d112f6e 100644
--- a/packages/frontend/vite.config.ts
+++ b/packages/frontend/vite.config.ts
@@ -101,11 +101,6 @@ export function getConfig(): UserConfig {
 			__VUE_PROD_DEVTOOLS__: false,
 		},
 
-		// https://vitejs.dev/guide/dep-pre-bundling.html#monorepos-and-linked-dependencies
-		optimizeDeps: {
-			include: ['misskey-js', 'misskey-reversi', 'misskey-bubble-game'],
-		},
-
 		build: {
 			target: [
 				'chrome116',
diff --git a/packages/misskey-bubble-game/package.json b/packages/misskey-bubble-game/package.json
index 852c923c3..787a95618 100644
--- a/packages/misskey-bubble-game/package.json
+++ b/packages/misskey-bubble-game/package.json
@@ -1,10 +1,22 @@
 {
+	"type": "module",
 	"name": "misskey-bubble-game",
 	"version": "0.0.1",
-	"main": "./built/index.js",
-	"types": "./built/index.d.ts",
+	"exports": {
+		".": {
+			"import": "./built/esm/index.js",
+			"types": "./built/dts/index.d.ts"
+		},
+		"./*": {
+			"import": "./built/esm/*",
+			"types": "./built/dts/*"
+		}
+	},
 	"scripts": {
-		"build": "tsc",
+		"build": "npm run ts",
+		"ts": "npm run ts-esm && npm run ts-dts",
+		"ts-esm": "tsc --outDir built/esm",
+		"ts-dts": "tsc --outDir built/dts --declaration true --emitDeclarationOnly true --declarationMap true",
 		"watch": "nodemon -w src -e ts,js,cjs,mjs,json --exec \"pnpm run build\"",
 		"eslint": "eslint . --ext .js,.jsx,.ts,.tsx",
 		"typecheck": "tsc --noEmit",
diff --git a/packages/misskey-js/package.json b/packages/misskey-js/package.json
index 1e3ed99a9..4c2d9e725 100644
--- a/packages/misskey-js/package.json
+++ b/packages/misskey-js/package.json
@@ -1,11 +1,23 @@
 {
+	"type": "module",
 	"name": "misskey-js",
 	"version": "0.0.16",
 	"description": "Misskey SDK for JavaScript",
-	"main": "./built/index.js",
-	"types": "./built/index.d.ts",
+	"exports": {
+		".": {
+			"import": "./built/esm/index.js",
+			"types": "./built/dts/index.d.ts"
+		},
+		"./*": {
+			"import": "./built/esm/*",
+			"types": "./built/dts/*"
+		}
+	},
 	"scripts": {
-		"build": "tsc",
+		"build": "npm run ts",
+		"ts": "npm run ts-esm && npm run ts-dts",
+		"ts-esm": "tsc --outDir built/esm",
+		"ts-dts": "tsc --outDir built/dts --declaration true --emitDeclarationOnly true --declarationMap true",
 		"watch": "nodemon -w src -e ts,js,cjs,mjs,json --exec \"pnpm run build\"",
 		"tsd": "tsd",
 		"api": "pnpm api-extractor run --local --verbose",
diff --git a/packages/misskey-js/src/api.ts b/packages/misskey-js/src/api.ts
index 0d10faaad..2e85fc293 100644
--- a/packages/misskey-js/src/api.ts
+++ b/packages/misskey-js/src/api.ts
@@ -1,11 +1,11 @@
-import './autogen/apiClientJSDoc';
+import './autogen/apiClientJSDoc.js';
 
-import { SwitchCaseResponseType } from './api.types';
-import type { Endpoints } from './api.types';
+import { SwitchCaseResponseType } from './api.types.js';
+import type { Endpoints } from './api.types.js';
 
 export {
 	SwitchCaseResponseType,
-} from './api.types';
+} from './api.types.js';
 
 const MK_API_ERROR = Symbol();
 
diff --git a/packages/misskey-js/src/api.types.ts b/packages/misskey-js/src/api.types.ts
index 75ab7d91b..632008192 100644
--- a/packages/misskey-js/src/api.types.ts
+++ b/packages/misskey-js/src/api.types.ts
@@ -1,6 +1,6 @@
-import { Endpoints as Gen } from './autogen/endpoint';
-import { UserDetailed } from './autogen/models';
-import { UsersShowRequest } from './autogen/entities';
+import { Endpoints as Gen } from './autogen/endpoint.js';
+import { UserDetailed } from './autogen/models.js';
+import { UsersShowRequest } from './autogen/entities.js';
 import {
 	SigninRequest,
 	SigninResponse,
@@ -8,7 +8,7 @@ import {
 	SignupPendingResponse,
 	SignupRequest,
 	SignupResponse,
-} from './entities';
+} from './entities.js';
 
 type Overwrite<T, U extends { [Key in keyof T]?: unknown }> = Omit<
 	T,
diff --git a/packages/misskey-js/src/entities.ts b/packages/misskey-js/src/entities.ts
index e00e192e0..bab518e63 100644
--- a/packages/misskey-js/src/entities.ts
+++ b/packages/misskey-js/src/entities.ts
@@ -1,8 +1,8 @@
 import { ModerationLogPayloads } from './consts.js';
-import { Announcement, EmojiDetailed, MeDetailed, MeDetailedOnly, Page, User, UserDetailed } from './autogen/models';
+import { Announcement, EmojiDetailed, MeDetailed, MeDetailedOnly, Page, User, UserDetailed } from './autogen/models.js';
 
-export * from './autogen/entities';
-export * from './autogen/models';
+export * from './autogen/entities.js';
+export * from './autogen/models.js';
 
 export type ID = string;
 export type DateString = string;
diff --git a/packages/misskey-js/src/streaming.ts b/packages/misskey-js/src/streaming.ts
index c641706a4..0f2685778 100644
--- a/packages/misskey-js/src/streaming.ts
+++ b/packages/misskey-js/src/streaming.ts
@@ -1,7 +1,9 @@
 import { EventEmitter } from 'eventemitter3';
-import ReconnectingWebsocket from 'reconnecting-websocket';
+import _ReconnectingWebsocket from 'reconnecting-websocket';
 import type { BroadcastEvents, Channels } from './streaming.types.js';
 
+const ReconnectingWebsocket = _ReconnectingWebsocket as unknown as typeof _ReconnectingWebsocket['default'];
+
 export function urlQuery(obj: Record<string, string | number | boolean | undefined>): string {
 	const params = Object.entries(obj)
 		.filter(([, v]) => Array.isArray(v) ? v.length : v !== undefined)
@@ -24,7 +26,7 @@ type StreamEvents = {
  * Misskey stream connection
  */
 export default class Stream extends EventEmitter<StreamEvents> {
-	private stream: ReconnectingWebsocket;
+	private stream: _ReconnectingWebsocket.default;
 	public state: 'initializing' | 'reconnecting' | 'connected' = 'initializing';
 	private sharedConnectionPools: Pool[] = [];
 	private sharedConnections: SharedConnection[] = [];