diff --git a/src/plugins/qmldesigner/designercore/instances/puppetcreator.cpp b/src/plugins/qmldesigner/designercore/instances/puppetcreator.cpp
index c5bb6e9d126..6937ece5c4a 100644
--- a/src/plugins/qmldesigner/designercore/instances/puppetcreator.cpp
+++ b/src/plugins/qmldesigner/designercore/instances/puppetcreator.cpp
@@ -433,7 +433,8 @@ QProcessEnvironment PuppetCreator::processEnvironment() const
     environment.set(QLatin1String("QML_USE_MOCKUPS"), QLatin1String("true"));
     environment.set(QLatin1String("QML_PUPPET_MODE"), QLatin1String("true"));
     environment.set(QLatin1String("QML_DISABLE_DISK_CACHE"), QLatin1String("true"));
-    environment.set(QLatin1String("QT_AUTO_SCREEN_SCALE_FACTOR"), QLatin1String("1"));
+    if (!environment.hasKey("QT_SCREEN_SCALE_FACTORS"))
+        environment.set(QLatin1String("QT_AUTO_SCREEN_SCALE_FACTOR"), QLatin1String("1"));
 
 #ifndef QMLDESIGNER_TEST
     const QString controlsStyle = m_designerSettings.value(DesignerSettingsKey::