diff --git a/Disp/DemoUtil.cs b/Disp/DemoUtil.cs
index bbe229e..9a90e75 100644
--- a/Disp/DemoUtil.cs
+++ b/Disp/DemoUtil.cs
@@ -1,7 +1,6 @@
 using Hi.Disp;
 using Hi.HiNcKits;
 using Hi.Licenses;
-using Hi.MongoUtils;
 using Hi.WpfPlus.Disp;
 using System.Windows;