diff --git a/src/private/DockRegistry.cpp b/src/private/DockRegistry.cpp
index 7c758392..815a4617 100644
--- a/src/private/DockRegistry.cpp
+++ b/src/private/DockRegistry.cpp
@@ -476,7 +476,7 @@ bool DockRegistry::isSane() const
             names.insert(name);
         }
 
-        if (!mainwindow->multiSplitter()->checkSanity())
+        if (!mainwindow->layoutWidget()->checkSanity())
             return false;
     }
 
@@ -684,7 +684,7 @@ void DockRegistry::clear(const DockWidgetBase::List &dockWidgets,
 
     for (auto mw : qAsConst(mainWindows)) {
         if (affinities.isEmpty() || affinitiesMatch(affinities, mw->affinities())) {
-            mw->multiSplitter()->clearLayout();
+            mw->layoutWidget()->clearLayout();
         }
     }
 }
diff --git a/tests/tst_docks.cpp b/tests/tst_docks.cpp
index 36572dab..05cda6b2 100644
--- a/tests/tst_docks.cpp
+++ b/tests/tst_docks.cpp
@@ -7797,6 +7797,11 @@ void TestDocks::tst_addMDIDockWidget()
     auto m = createMainWindow(QSize(800, 500), MainWindowOption_MDI);
     auto dock0 = createDockWidget("dock0", new MyWidget2(QSize(400, 400)));
     qobject_cast<MDILayoutWidget *>(m->layoutWidget())->addDockWidget(dock0, QPoint(0, 0), {});
+
+    // MDI doesn't support LayoutSaver yet, but it was crashing, so add a test
+    // to catch further crashes
+    LayoutSaver saver;
+    const QByteArray saved = saver.serializeLayout();
 }
 
 void TestDocks::tst_redockToMDIRestoresPosition()