diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index 738c3846c53..ee947c0c5f8 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -1093,7 +1093,9 @@ QThreadData *QThreadData::current(bool createIfNecessary)
         data->deref();
         data->isAdopted = true;
         if (!QCoreApplicationPrivate::theMainThreadId.loadAcquire()) {
-            QCoreApplicationPrivate::theMainThread.storeRelease(data->thread.loadRelaxed());
+            auto *mainThread = data->thread.loadRelaxed();
+            mainThread->setObjectName("Qt mainThread");
+            QCoreApplicationPrivate::theMainThread.storeRelease(mainThread);
             QCoreApplicationPrivate::theMainThreadId.storeRelaxed(data->threadId.loadRelaxed());
         }
     }
diff --git a/src/corelib/thread/qthread_unix.cpp b/src/corelib/thread/qthread_unix.cpp
index 13b061d7c7e..22f0489c770 100644
--- a/src/corelib/thread/qthread_unix.cpp
+++ b/src/corelib/thread/qthread_unix.cpp
@@ -189,7 +189,9 @@ QThreadData *QThreadData::current(bool createIfNecessary)
         data->isAdopted = true;
         data->threadId.storeRelaxed(to_HANDLE(pthread_self()));
         if (!QCoreApplicationPrivate::theMainThreadId.loadAcquire()) {
-            QCoreApplicationPrivate::theMainThread.storeRelease(data->thread.loadRelaxed());
+            auto *mainThread = data->thread.loadRelaxed();
+            mainThread->setObjectName("Qt mainThread");
+            QCoreApplicationPrivate::theMainThread.storeRelease(mainThread);
             QCoreApplicationPrivate::theMainThreadId.storeRelaxed(data->threadId.loadRelaxed());
         }
     }
diff --git a/src/corelib/thread/qthread_win.cpp b/src/corelib/thread/qthread_win.cpp
index 74bc1d26505..0fba38d250b 100644
--- a/src/corelib/thread/qthread_win.cpp
+++ b/src/corelib/thread/qthread_win.cpp
@@ -88,7 +88,9 @@ QThreadData *QThreadData::current(bool createIfNecessary)
         threadData->threadId.storeRelaxed(reinterpret_cast<Qt::HANDLE>(quintptr(GetCurrentThreadId())));
 
         if (!QCoreApplicationPrivate::theMainThreadId) {
-            QCoreApplicationPrivate::theMainThread.storeRelease(threadData->thread.loadRelaxed());
+            auto *mainThread = threadData->thread.loadRelaxed();
+            mainThread->setObjectName("Qt mainThread");
+            QCoreApplicationPrivate::theMainThread.storeRelease(mainThread);
             QCoreApplicationPrivate::theMainThreadId.storeRelaxed(threadData->threadId.loadRelaxed());
         } else {
             HANDLE realHandle = INVALID_HANDLE_VALUE;