diff --git a/kded/serializer.cpp b/kded/serializer.cpp
--- a/kded/serializer.cpp
+++ b/kded/serializer.cpp
@@ -256,6 +256,7 @@
         output->setPrimary(info[QStringLiteral("primary")].toBool());
         output->setEnabled(info[QStringLiteral("enabled")].toBool());
         output->setRotation(static_cast<KScreen::Output::Rotation>(info[QStringLiteral("rotation")].toInt()));
+        output->setScale(info.value(QStringLiteral("scale"), 1).toInt());
 
         const QVariantMap modeInfo = info[QStringLiteral("mode")].toMap();
         const QVariantMap modeSize = modeInfo[QStringLiteral("size")].toMap();