diff --git a/kcm/src/widget.cpp b/kcm/src/widget.cpp
--- a/kcm/src/widget.cpp
+++ b/kcm/src/widget.cpp
@@ -45,6 +45,7 @@
 #include <QPushButton>
 #include <QQuickView>
 #include <QQuickWidget>
+#include <QScreen>
 
 #include "ui_kscreen_widget.h"
 
@@ -446,6 +447,13 @@
         const KScreen::ModePtr mode = output->currentMode();
 
         QQuickView *view = new QQuickView();
+        const auto screens = QGuiApplication::screens();
+        for (QScreen *screen : screens) {
+            if (output->pos() == screen->geometry().topLeft()) {
+                view->setScreen(screen);
+                break;
+            }
+        }
 
         view->setFlags(Qt::X11BypassWindowManagerHint | Qt::FramelessWindowHint);
         view->setResizeMode(QQuickView::SizeViewToRootObject);
@@ -468,7 +476,8 @@
             // no scale adjustment needed on Wayland
             logicalSize = deviceSize;
         } else {
-            logicalSize = deviceSize / devicePixelRatioF();
+            const QScreen *screen = view->screen();
+            logicalSize = screen ? screen->size() : deviceSize / devicePixelRatioF();
         }
 
         rootObj->setProperty("outputName", Utils::outputName(output));