diff --git a/packages/emnapi/src/core/async-work.ts b/packages/emnapi/src/core/async-work.ts
index 3e76f0dd..e2ace373 100644
--- a/packages/emnapi/src/core/async-work.ts
+++ b/packages/emnapi/src/core/async-work.ts
@@ -57,7 +57,7 @@ var emnapiAWMT = {
 
     if (typeof PThread !== 'undefined') {
       PThread.unusedWorkers.forEach(emnapiAWMT.addListener)
-      PThread.runningWorkers.forEach(emnapiAWMT.addListener)
+      Object.values(PThread.pthreads).forEach(emnapiAWMT.addListener)
       const __original_getNewWorker = PThread.getNewWorker
       PThread.getNewWorker = function () {
         const r = __original_getNewWorker.apply(this, arguments as any)
diff --git a/packages/emnapi/src/emscripten/async.ts b/packages/emnapi/src/emscripten/async.ts
index e896db32..cd89d00c 100644
--- a/packages/emnapi/src/emscripten/async.ts
+++ b/packages/emnapi/src/emscripten/async.ts
@@ -34,7 +34,7 @@ export function _emnapi_worker_unref (pid: number): void {
  * @__postset
  * ```
  * PThread.unusedWorkers.forEach(emnapiAddSendListener);
- * PThread.runningWorkers.forEach(emnapiAddSendListener);
+ * Object.values(PThread.pthreads).forEach(emnapiAddSendListener);
  * (function () {
  *   var __original_getNewWorker = PThread.getNewWorker;
  *   PThread.getNewWorker = function () {
diff --git a/packages/emnapi/src/threadsafe-function.ts b/packages/emnapi/src/threadsafe-function.ts
index a8de457f..ee0effb5 100644
--- a/packages/emnapi/src/threadsafe-function.ts
+++ b/packages/emnapi/src/threadsafe-function.ts
@@ -119,7 +119,7 @@ const emnapiTSFN = {
     emnapiTSFN.offset.mutex = emnapiTSFN.offset.mutex + 4
     if (typeof PThread !== 'undefined') {
       PThread.unusedWorkers.forEach(emnapiTSFN.addListener)
-      PThread.runningWorkers.forEach(emnapiTSFN.addListener)
+      Object.values(PThread.pthreads).forEach(emnapiTSFN.addListener)
       const __original_getNewWorker = PThread.getNewWorker
       PThread.getNewWorker = function () {
         const r = __original_getNewWorker.apply(this, arguments as any)
diff --git a/packages/wasi-threads/src/thread-manager.ts b/packages/wasi-threads/src/thread-manager.ts
index 569fc115..81f6c14f 100644
--- a/packages/wasi-threads/src/thread-manager.ts
+++ b/packages/wasi-threads/src/thread-manager.ts
@@ -96,7 +96,6 @@ let nextWorkerID = 0
 /** @public */
 export class ThreadManager {
   public unusedWorkers: WorkerLike[] = []
-  public runningWorkers: WorkerLike[] = []
   public pthreads: Record<number, WorkerLike> = Object.create(null)
   public get nextWorkerID (): number { return nextWorkerID }
 
@@ -218,7 +217,6 @@ export class ThreadManager {
       delete this.pthreads[tid]
     }
     this.unusedWorkers.push(worker)
-    this.runningWorkers.splice(this.runningWorkers.indexOf(worker), 1)
     delete worker.__emnapi_tid
     if (ENVIRONMENT_IS_NODE) {
       (worker as NodeWorker).unref()
@@ -351,10 +349,6 @@ export class ThreadManager {
       this.returnWorkerToPool(worker)
     } else {
       delete this.pthreads[tid]
-      const index = this.runningWorkers.indexOf(worker)
-      if (index !== -1) {
-        this.runningWorkers.splice(index, 1)
-      }
       this.terminateWorker(worker)
       delete worker.__emnapi_tid
     }
@@ -375,14 +369,14 @@ export class ThreadManager {
   }
 
   public terminateAllThreads (): void {
-    for (let i = 0; i < this.runningWorkers.length; ++i) {
-      this.terminateWorker(this.runningWorkers[i])
+    const runningWorkers = Object.values(this.pthreads)
+    for (let i = 0; i < runningWorkers.length; ++i) {
+      this.terminateWorker(runningWorkers[i])
     }
     for (let i = 0; i < this.unusedWorkers.length; ++i) {
       this.terminateWorker(this.unusedWorkers[i])
     }
     this.unusedWorkers = []
-    this.runningWorkers = []
     this.pthreads = Object.create(null)
 
     this.preparePool()
diff --git a/packages/wasi-threads/src/wasi-threads.ts b/packages/wasi-threads/src/wasi-threads.ts
index 9ec3e9e7..0478d949 100644
--- a/packages/wasi-threads/src/wasi-threads.ts
+++ b/packages/wasi-threads/src/wasi-threads.ts
@@ -173,7 +173,7 @@ export class WASIThreads {
       }
 
       let worker: WorkerLike | undefined
-      let tid: number
+      let tid: number | undefined
       const PThread = this.PThread
       try {
         worker = PThread!.getNewWorker(sab)
@@ -194,9 +194,6 @@ export class WASIThreads {
           if (typeof waitThreadStart === 'number') {
             const waitResult = Atomics.wait(sab!, 0, 0, waitThreadStart)
             if (waitResult === 'timed-out') {
-              try {
-                PThread!.cleanThread(worker, tid, true)
-              } catch (_) {}
               throw new Error('Spawning thread timed out. Please check if the worker is created successfully and if message is handled properly in the worker.')
             }
           } else {
@@ -204,13 +201,15 @@ export class WASIThreads {
           }
           const r = Atomics.load(sab!, 0)
           if (r > 1) {
-            try {
-              PThread!.cleanThread(worker, tid, true)
-            } catch (_) {}
             throw deserizeErrorFromBuffer(sab!.buffer as SharedArrayBuffer)!
           }
         }
       } catch (e) {
+        if (worker !== undefined && tid !== undefined) {
+          try {
+            PThread!.cleanThread(worker, tid, true)
+          } catch (_) {}
+        }
         Atomics.store(struct, 0, 1)
         Atomics.store(struct, 1, EAGAIN)
         Atomics.notify(struct, 1)
@@ -227,7 +226,6 @@ export class WASIThreads {
       Atomics.store(struct, 1, tid)
       Atomics.notify(struct, 1)
 
-      PThread!.runningWorkers.push(worker)
       if (!shouldWait) {
         worker.whenLoaded!.catch((err: any) => {
           delete worker.whenLoaded