--- a/xpcom/threads/nsThreadPool.cpp
+++ b/xpcom/threads/nsThreadPool.cpp
@@ -99,18 +99,19 @@ nsThreadPool::PutEvent(already_AddRefed<
   }
 
   LOG(("THRD-P(%p) put [spawn=%d]\n", this, spawnThread));
   if (!spawnThread) {
     return NS_OK;
   }
 
   nsCOMPtr<nsIThread> thread;
-  nsThreadManager::get().NewThread(0, stackSize, getter_AddRefs(thread));
-  if (NS_WARN_IF(!thread)) {
+  nsresult rv = NS_NewNamedThread(mThreadNaming.GetNextThreadName(mName),
+                                  getter_AddRefs(thread), nullptr, stackSize);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
     return NS_ERROR_UNEXPECTED;
   }
 
   bool killThread = false;
   {
     MutexAutoLock lock(mMutex);
     if (mThreads.Count() < (int32_t)mThreadLimit) {
       mThreads.AppendObject(thread);
@@ -147,18 +148,16 @@ nsThreadPool::ShutdownThread(nsIThread* 
   // shutdown aThread from the main thread.
   NS_DispatchToMainThread(NewRunnableMethod(aThread,
                                             &nsIThread::AsyncShutdown));
 }
 
 NS_IMETHODIMP
 nsThreadPool::Run()
 {
-  mThreadNaming.SetThreadPoolName(mName);
-
   LOG(("THRD-P(%p) enter %s\n", this, mName.BeginReading()));
 
   nsCOMPtr<nsIThread> current;
   nsThreadManager::get().GetCurrentThread(getter_AddRefs(current));
 
   bool shutdownThreadOnExit = false;
   bool exitThread = false;
   bool wasIdle = false;