diff --git a/autotests/testkwaylandbackend.cpp b/autotests/testkwaylandbackend.cpp
--- a/autotests/testkwaylandbackend.cpp
+++ b/autotests/testkwaylandbackend.cpp
@@ -151,6 +151,7 @@
         QVERIFY(output->geometry() != QRectF());
         QVERIFY(output->sizeMm() != QSize());
         QVERIFY(output->edid() != 0);
+        QVERIFY(output->preferredModes().size() == 1);
         QCOMPARE(output->rotation(), Output::None);
         QVERIFY(!ids.contains(output->id()));
         ids << output->id();
diff --git a/backends/kwayland/waylandoutput.cpp b/backends/kwayland/waylandoutput.cpp
--- a/backends/kwayland/waylandoutput.cpp
+++ b/backends/kwayland/waylandoutput.cpp
@@ -131,6 +131,7 @@
     output->setPos(m_output->globalPosition());
     output->setRotation(m_rotationMap[m_output->transform()]);
     KScreen::ModeList modeList;
+    QStringList preferredModeIds;
     m_modeIdMap.clear();
     QString currentModeId = QStringLiteral("-1");
     Q_FOREACH (const KWayland::Client::OutputDevice::Mode &m, m_output->modes()) {
@@ -152,6 +153,9 @@
         if (m.flags.testFlag(KWayland::Client::OutputDevice::Mode::Flag::Current)) {
             currentModeId = modeid;
         }
+        if (m.flags.testFlag(KWayland::Client::OutputDevice::Mode::Flag::Preferred)) {
+            preferredModeIds << modeid;
+        }
         // Update the kscreen => kwayland mode id translation map
         m_modeIdMap.insert(modeid, m.id);
         // Add to the modelist which gets set on the output
@@ -162,6 +166,7 @@
     }
     output->setCurrentModeId(currentModeId);
 
+    output->setPreferredModes(preferredModeIds);
     output->setModes(modeList);
     output->setScale(m_output->scale());
 }