diff --git a/host/javascript/package.json b/host/javascript/package.json
index da2ccab8..55e91f22 100644
--- a/host/javascript/package.json
+++ b/host/javascript/package.json
@@ -7,11 +7,6 @@
     "./cloudflare": "./cloudflare/index.js",
     "./cloudflare/index.js": "./cloudflare/index.js",
     "./common": "./common/index.js",
-    "./common/index.js": "./common/index.js",
-    "./common/app": "./common/app.js",
-    "./common/app.js": "./common/app.js",
-    "./node/error": "./node/error",
-    "./node/error.js": "./node/error.js",
     "./assets/core-async.wasm": "./assets/core-async.wasm"
   },
   "type": "module",
diff --git a/host/javascript/src/common/index.ts b/host/javascript/src/common/index.ts
index 21e509aa..8f3e6bdf 100644
--- a/host/javascript/src/common/index.ts
+++ b/host/javascript/src/common/index.ts
@@ -1,4 +1,4 @@
-export { App } from './app.js';
+export { App, AsyncMutex } from './app.js';
 export type { TextCoder, FileSystem, Timers, Network, WasiContext, Persistence } from './interfaces.js';
 export { HandleMap } from './handle_map.js';
 export { SecurityValuesMap } from './security.js';
diff --git a/host/javascript/src/node/index.ts b/host/javascript/src/node/index.ts
index e61d9f0f..c0740435 100644
--- a/host/javascript/src/node/index.ts
+++ b/host/javascript/src/node/index.ts
@@ -20,6 +20,7 @@ import {
 import { fetchErrorToHostError, systemErrorToWasiError } from './error.js';
 
 export { PerformError, UnexpectedError, ValidationError } from '../common/index.js';
+export { fetchErrorToHostError, systemErrorToWasiError } from './error.js';
 
 const CORE_PATH = process.env.CORE_PATH ?? createRequire(import.meta.url).resolve('../assets/core-async.wasm');
 const ASSETS_FOLDER = 'superface';