Index: Core/Gui/src/Core.Gui/Forms/Main/MainWindow.xaml.cs
===================================================================
diff -u -r42312b7efb17be543bfcba213b9c96c3aea0336c -r944d8f057924d6aa559f248328b07bf5d8607a7b
--- Core/Gui/src/Core.Gui/Forms/Main/MainWindow.xaml.cs	(.../MainWindow.xaml.cs)	(revision 42312b7efb17be543bfcba213b9c96c3aea0336c)
+++ Core/Gui/src/Core.Gui/Forms/Main/MainWindow.xaml.cs	(.../MainWindow.xaml.cs)	(revision 944d8f057924d6aa559f248328b07bf5d8607a7b)
@@ -46,7 +46,7 @@
 using Core.Gui.Selection;
 using Core.Gui.Settings;
 using FontFamily = System.Windows.Media.FontFamily;
-using FormsControl = System.Windows.Forms.Control;
+using UserControl = System.Windows.Forms.UserControl;
 
 namespace Core.Gui.Forms.Main
 {
@@ -628,15 +628,15 @@
         private void OnViewOpened(object sender, ViewChangeEventArgs e)
         {
             var mapView = e.View as IMapView;
-            if (mapView != null && e.View is FormsControl mapControl)
+            if (mapView != null && e.View is UserControl mapUserControl)
             {
-                mapControl.VisibleChanged += MapViewVisibleChanged;
+                mapUserControl.VisibleChanged += MapViewVisibleChanged;
             }
 
             var chartView = e.View as IChartView;
-            if (chartView != null && e.View is FormsControl chartControl)
+            if (chartView != null && e.View is UserControl chartUserControl)
             {
-                chartControl.VisibleChanged += ChartViewVisibleChanged;
+                chartUserControl.VisibleChanged += ChartViewVisibleChanged;
             }
 
             UpdateComponentsForMapView(mapView);
@@ -655,7 +655,7 @@
         /// </summary>
         private static void MapViewVisibleChanged(object sender, EventArgs e)
         {
-            var control = (FormsControl) sender;
+            var control = (UserControl) sender;
             if (control.Width != 0.0 && control.Height != 0.0)
             {
                 ((IMapView) control).Map.ZoomToVisibleLayers();
@@ -669,7 +669,7 @@
         /// </summary>
         private static void ChartViewVisibleChanged(object sender, EventArgs e)
         {
-            var control = (FormsControl) sender;
+            var control = (UserControl) sender;
             if (control.Width != 0.0 && control.Height != 0.0)
             {
                 IChartControl chartControl = ((IChartView) control).Chart;
Index: Core/Gui/test/Core.Gui.Test/Forms/Main/MainWindowTest.cs
===================================================================
diff -u -r965969ab5313efefaacc530d26242f9f1980882b -r944d8f057924d6aa559f248328b07bf5d8607a7b
--- Core/Gui/test/Core.Gui.Test/Forms/Main/MainWindowTest.cs	(.../MainWindowTest.cs)	(revision 965969ab5313efefaacc530d26242f9f1980882b)
+++ Core/Gui/test/Core.Gui.Test/Forms/Main/MainWindowTest.cs	(.../MainWindowTest.cs)	(revision 944d8f057924d6aa559f248328b07bf5d8607a7b)
@@ -654,12 +654,9 @@
 
                 // When
                 gui.ViewHost.AddDocumentView(testMapView);
-                
-                testMapView.VisibleChanged += (sender, args) =>
-                {
-                    // Then
-                    Assert.AreNotEqual(initialExtents, map.ViewExtents);
-                };
+
+                // Then
+                Assert.AreNotEqual(initialExtents, map.ViewExtents);
             }
 
             mocks.VerifyAll();