diff --git a/tests/gtk/test_window.py b/tests/gtk/test_window.py
index 3d1d234..1be4dc5 100644
--- a/tests/gtk/test_window.py
+++ b/tests/gtk/test_window.py
@@ -38,21 +38,25 @@ class TestWindow(unittest.TestCase):
         self.assertEqual(self.window.headerbar.props.title_widget,
                          self.window.title)
 
-    def test_child(self):
-        """Test the window child property."""
-        self.assertIsInstance(self.window.headerbar.get_next_sibling(),
-                              Adw.Bin)
+    def test_splitview(self):
+        """Check that the Window's splitview is set up correctly."""
+        self.assertIsInstance(self.window._splitview, Adw.OverlaySplitView)
+        self.assertEqual(self.window.headerbar.get_next_sibling(),
+                         self.window._splitview)
+        self.assertFalse(self.window._splitview.props.show_sidebar)
+        self.assertTrue(self.window._splitview.props.collapsed)
 
+    def test_content(self):
+        """Test the window content property."""
         self.assertIsNone(self.window.child)
         self.window.child = Gtk.Label()
-        self.assertEqual(self.window.headerbar.get_next_sibling().props.child,
+        self.assertEqual(self.window._splitview.props.content,
                          self.window.child)
 
         label = Gtk.Label()
         window2 = xfstestsdb.gtk.window.Window(child=label)
         self.assertEqual(window2.child, label)
-        self.assertEqual(window2.headerbar.get_next_sibling().props.child,
-                         label)
+        self.assertEqual(window2._splitview.props.content, label)
 
     def test_runid(self):
         """Test the window runid property."""
diff --git a/xfstestsdb/gtk/window.py b/xfstestsdb/gtk/window.py
index fd06acd..c6520ed 100644
--- a/xfstestsdb/gtk/window.py
+++ b/xfstestsdb/gtk/window.py
@@ -20,13 +20,17 @@ class Window(Adw.Window):
                          content=Gtk.Box(orientation=Gtk.Orientation.VERTICAL),
                          title=Adw.WindowTitle(title="xfstestsdb gtk"),
                          headerbar=Adw.HeaderBar(), **kwargs)
+        self._splitview = Adw.OverlaySplitView(content=self.child,
+                                               collapsed=True,
+                                               show_sidebar=False)
+
         self.headerbar.props.title_widget = self.title
         self.headerbar.add_css_class("flat")
 
         self.props.content.append(self.headerbar)
-        self.props.content.append(Adw.Bin(child=self.child))
+        self.props.content.append(self._splitview)
 
-        self.bind_property("child", self.headerbar.get_next_sibling(), "child")
+        self.bind_property("child", self._splitview, "content")
         self.connect("notify::runid", self.__notify_runid)
 
         if __debug__: