From 8c622ba1882c249e741659be7b5e5c4ba267b291 Mon Sep 17 00:00:00 2001
From: sta <sta.blockhead@gmail.com>
Date: Mon, 17 Aug 2020 22:14:26 +0900
Subject: [PATCH] [Modify] Polish it

---
 websocket-sharp/Net/HttpListenerPrefixCollection.cs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/websocket-sharp/Net/HttpListenerPrefixCollection.cs b/websocket-sharp/Net/HttpListenerPrefixCollection.cs
index 450c2986..6e2b2118 100644
--- a/websocket-sharp/Net/HttpListenerPrefixCollection.cs
+++ b/websocket-sharp/Net/HttpListenerPrefixCollection.cs
@@ -163,8 +163,11 @@ namespace WebSocketSharp.Net
     {
       _listener.CheckDisposed ();
       _prefixes.Clear ();
-      if (_listener.IsListening)
-        EndPointManager.RemoveListener (_listener);
+
+      if (!_listener.IsListening)
+        return;
+
+      EndPointManager.RemoveListener (_listener);
     }
 
     /// <summary>