diff --git a/shadowsocks-csharp/View/ConfigForm.cs b/shadowsocks-csharp/View/ConfigForm.cs
index 3a4e5e04..db695ae9 100755
--- a/shadowsocks-csharp/View/ConfigForm.cs
+++ b/shadowsocks-csharp/View/ConfigForm.cs
@@ -151,7 +151,7 @@ namespace Shadowsocks.View
             _modifiedConfiguration = controller.GetConfigurationCopy();
             LoadConfiguration(_modifiedConfiguration);
             _lastSelectedIndex = _modifiedConfiguration.index;
-            if (_lastSelectedIndex < 0)
+            if (_lastSelectedIndex < 0 || _lastSelectedIndex >= ServersListBox.Items.Count)
             {
                 _lastSelectedIndex = 0;
             }