diff --git a/ksmserver/main.cpp b/ksmserver/main.cpp
--- a/ksmserver/main.cpp
+++ b/ksmserver/main.cpp
@@ -238,6 +238,7 @@
     qputenv("QT_QPA_PLATFORM", QByteArrayLiteral("xcb"));
 
     QQuickWindow::setDefaultAlphaBuffer(true);
+    QCoreApplication::setAttribute(Qt::AA_DisableHighDpiScaling);
     QApplication *a = new QApplication(argc, argv);
 
     // now the QPA platform is set, unset variable again to not launch apps with incorrect environment