diff --git a/SampleApps/WinUiApp/MainWindow.xaml b/SampleApps/WinUiApp/MainWindow.xaml
index b7a963bb..0e782036 100644
--- a/SampleApps/WinUiApp/MainWindow.xaml
+++ b/SampleApps/WinUiApp/MainWindow.xaml
@@ -7,6 +7,13 @@
 
     <Grid>
         <Grid.Resources>
+            <!--
+            XAML declaration of BingMapsTileLayer is necessary to make Value="{Binding LoadingProgress}"
+            on the ProgressBar below work. Apparently dependency properties of custom types do not fire
+            change notifications when the type is not declared in XAML. To be reported as WinUI issue.
+            -->
+            <map:BingMapsTileLayer x:Key="dummy"/>
+
             <DataTemplate x:Key="PolylineItemTemplate">
                 <map:MapPolyline Locations="{Binding Locations}" Stroke="Red" StrokeThickness="3"/>
             </DataTemplate>