diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 553eaf0820..3ae4e523c8 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -146,6 +146,9 @@ QString QCoreApplicationPrivate::macMenuBarName()
 #endif
 QString QCoreApplicationPrivate::appName() const
 {
+    static QBasicMutex applicationNameMutex;
+    QMutexLocker locker(&applicationNameMutex);
+
     if (applicationName.isNull()) {
 #ifdef Q_OS_MAC
         applicationName = macMenuBarName();