diff --git a/src/corelib/thread/qthread_win.cpp b/src/corelib/thread/qthread_win.cpp
index f53e488a8d7..9ab1cf718ea 100644
--- a/src/corelib/thread/qthread_win.cpp
+++ b/src/corelib/thread/qthread_win.cpp
@@ -314,7 +314,7 @@ void QThread::msleep(unsigned long msecs)
 
 void QThread::usleep(unsigned long usecs)
 {
-    ::Sleep((usecs / 1000) + 1);
+    ::Sleep((usecs + 999) / 1000);
 }
 
 #if QT_CONFIG(thread)