diff --git a/src/Avalonia.X11/X11Window.cs b/src/Avalonia.X11/X11Window.cs
index 6ff5b96f12..d2fe69862b 100644
--- a/src/Avalonia.X11/X11Window.cs
+++ b/src/Avalonia.X11/X11Window.cs
@@ -133,9 +133,9 @@ namespace Avalonia.X11
                 _renderHandle = _handle;
                 
             Handle = new PlatformHandle(_handle, "XID");
-            _realSize = new PixelSize(300, 200);
+            _realSize = new PixelSize(defaultWidth, defaultHeight);
             platform.Windows[_handle] = OnEvent;
-            XEventMask ignoredMask = XEventMask.SubstructureRedirectMask
+            var ignoredMask = XEventMask.SubstructureRedirectMask
                                      | XEventMask.ResizeRedirectMask
                                      | XEventMask.PointerMotionHintMask;
             if (platform.XI2 != null)
@@ -176,6 +176,7 @@ namespace Avalonia.X11
                 PopupPositioner = new ManagedPopupPositioner(new ManagedPopupPositionerPopupImplHelper(popupParent, MoveResize));
             if (platform.Options.UseDBusMenu)
                 NativeMenuExporter = DBusMenuExporter.TryCreate(_handle);
+            XSync(_x11.Display, true);
         }
 
         class SurfaceInfo  : EglGlPlatformSurface.IEglWindowGlPlatformSurfaceInfo