diff --git a/v2rayN/v2rayN/Forms/MainForm.cs b/v2rayN/v2rayN/Forms/MainForm.cs
index 097c220e..d8375be7 100644
--- a/v2rayN/v2rayN/Forms/MainForm.cs
+++ b/v2rayN/v2rayN/Forms/MainForm.cs
@@ -1007,8 +1007,11 @@ namespace v2rayN.Forms
 
         private void SetTestResult(int k, string txt)
         {
-            config.vmess[k].testResult = txt;
-            lvServers.Items[k].SubItems["testResult"].Text = txt;
+            if (k < lvServers.Items.Count)
+            {
+                config.vmess[k].testResult = txt;
+                lvServers.Items[k].SubItems["testResult"].Text = txt;
+            }
         }
         private void ClearTestResult()
         {