diff --git a/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs b/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs
index e0a2f31896..f995266b6c 100644
--- a/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs
+++ b/src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs
@@ -27,7 +27,7 @@ namespace ICSharpCode.SharpDevelop.Gui
 	/// <summary>
 	/// Workbench implementation using WPF and AvalonDock.
 	/// </summary>
-	sealed partial class WpfWorkbench : Window, IWorkbench
+	sealed partial class WpfWorkbench : Window, IWorkbench, System.Windows.Forms.IWin32Window
 	{
 		const string mainMenuPath    = "/SharpDevelop/Workbench/MainMenu";
 		const string viewContentPath = "/SharpDevelop/Workbench/Pads";
@@ -53,10 +53,20 @@ namespace ICSharpCode.SharpDevelop.Gui
 			}
 		}
 		
-		public System.Windows.Forms.IWin32Window MainWin32Window { get; private set; }
+		public System.Windows.Forms.IWin32Window MainWin32Window { get { return this; } }
 		public ISynchronizeInvoke SynchronizingObject { get; private set; }
 		public Window MainWindow { get { return this; } }
 		
+		IntPtr System.Windows.Forms.IWin32Window.Handle {
+			get {
+				var wnd = System.Windows.PresentationSource.FromVisual(this) as System.Windows.Interop.IWin32Window;
+				if (wnd != null)
+					return wnd.Handle;
+				else
+					return IntPtr.Zero;
+			}
+		}
+		
 		List<PadDescriptor> padDescriptorCollection = new List<PadDescriptor>();
 		
 		ToolBar[] toolBars;
@@ -70,7 +80,6 @@ namespace ICSharpCode.SharpDevelop.Gui
 		
 		protected override void OnSourceInitialized(EventArgs e)
 		{
-			this.MainWin32Window = this.GetWin32Window();
 			base.OnSourceInitialized(e);
 			HwndSource.FromHwnd(this.MainWin32Window.Handle).AddHook(SingleInstanceHelper.WndProc);
 		}
diff --git a/src/Main/Base/Project/Src/Gui/WorkbenchSingleton.cs b/src/Main/Base/Project/Src/Gui/WorkbenchSingleton.cs
index c4bc4e8ed1..37b18f926a 100644
--- a/src/Main/Base/Project/Src/Gui/WorkbenchSingleton.cs
+++ b/src/Main/Base/Project/Src/Gui/WorkbenchSingleton.cs
@@ -86,6 +86,7 @@ namespace ICSharpCode.SharpDevelop.Gui
 			
 			var messageService = (WinFormsMessageService)Core.Services.ServiceManager.Instance.MessageService;
 			messageService.DialogOwner = workbench.MainWin32Window;
+			Debug.Assert(messageService.DialogOwner != null);
 			messageService.DialogSynchronizeInvoke = workbench.SynchronizingObject;
 			
 			workbench.Initialize();
diff --git a/src/Main/Base/Project/Src/Util/ExtensionMethods.cs b/src/Main/Base/Project/Src/Util/ExtensionMethods.cs
index e2721c6e94..b7272307d5 100644
--- a/src/Main/Base/Project/Src/Util/ExtensionMethods.cs
+++ b/src/Main/Base/Project/Src/Util/ExtensionMethods.cs
@@ -134,32 +134,6 @@ namespace ICSharpCode.SharpDevelop
 			return result;
 		}
 		
-		/// <summary>
-		/// Gets the IWin32Window associated with a WPF window.
-		/// </summary>
-		public static WinForms.IWin32Window GetWin32Window(this System.Windows.Window window)
-		{
-			var wnd = System.Windows.PresentationSource.FromVisual(window) as System.Windows.Interop.IWin32Window;
-			if (wnd != null)
-				return new Win32WindowAdapter(wnd);
-			else
-				return null;
-		}
-		
-		sealed class Win32WindowAdapter : WinForms.IWin32Window
-		{
-			readonly System.Windows.Interop.IWin32Window window;
-			
-			public Win32WindowAdapter(System.Windows.Interop.IWin32Window window)
-			{
-				this.window = window;
-			}
-			
-			public IntPtr Handle {
-				get { return window.Handle; }
-			}
-		}
-		
 		/// <summary>
 		/// Sets the Content property of the specified ControlControl to the specified content.
 		/// If the content is a Windows-Forms control, it is wrapped in a WindowsFormsHost.