diff --git a/src/corelib/thread/qthread_p.h b/src/corelib/thread/qthread_p.h
index 4918fd7b852..e429362514d 100644
--- a/src/corelib/thread/qthread_p.h
+++ b/src/corelib/thread/qthread_p.h
@@ -188,6 +188,9 @@ public:
     bool finished;
     bool isInFinish; //when in QThreadPrivate::finish
     std::atomic<bool> interruptionRequested = false;
+#ifdef Q_OS_UNIX
+    bool terminated = false; // when (the first) terminate has been called
+#endif
 
     bool exited;
     int returnCode;
diff --git a/src/corelib/thread/qthread_unix.cpp b/src/corelib/thread/qthread_unix.cpp
index de18bcb0969..a56a764eed5 100644
--- a/src/corelib/thread/qthread_unix.cpp
+++ b/src/corelib/thread/qthread_unix.cpp
@@ -647,6 +647,7 @@ void QThread::start(Priority priority)
     d->returnCode = 0;
     d->exited = false;
     d->interruptionRequested.store(false, std::memory_order_relaxed);
+    d->terminated = false;
 
     pthread_attr_t attr;
     pthread_attr_init(&attr);
@@ -758,8 +759,14 @@ void QThread::terminate()
     if (!d->data->threadId.loadRelaxed())
         return;
 
+    if (d->terminated) // don't try again, avoids killing the wrong thread on threadId reuse (ABA)
+        return;
+
+    d->terminated = true;
+
     int code = pthread_cancel(from_HANDLE<pthread_t>(d->data->threadId.loadRelaxed()));
     if (code) {
+        d->terminated = false; // allow to try again
         qErrnoWarning(code, "QThread::start: Thread termination error");
     }
 #endif