diff --git a/source/Components/AvalonDock/Controls/LayoutDocumentPaneControl.cs b/source/Components/AvalonDock/Controls/LayoutDocumentPaneControl.cs
index 53944d2d..da2c900f 100644
--- a/source/Components/AvalonDock/Controls/LayoutDocumentPaneControl.cs
+++ b/source/Components/AvalonDock/Controls/LayoutDocumentPaneControl.cs
@@ -96,7 +96,7 @@ protected override void OnItemsChanged(NotifyCollectionChangedEventArgs e)
 			{
 				foreach (var item in e.OldItems)
 				{
-					if (item is LayoutContent layoutContent)
+					if (item is LayoutContent layoutContent && layoutContent.TabItem != null)
 					{
 						layoutContent.TabItem.Model = null;
 						layoutContent.TabItem.ContextMenu = null;