diff --git a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CaretReferencesRenderer.cs b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CaretReferencesRenderer.cs
index 13c17a0ff4..5122248643 100644
--- a/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CaretReferencesRenderer.cs
+++ b/src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CaretReferencesRenderer.cs
@@ -141,6 +141,8 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		/// </summary>
 		List<Reference> FindReferencesInCurrentFile(ResolveResult resolveResult)
 		{
+			if (resolveResult == null)
+				return null;
 			var cancellationTokenSource = new CancellationTokenSource();
 			using (new Timer(
 				delegate {