diff --git a/websocket-sharp/Net/EndPointManager.cs b/websocket-sharp/Net/EndPointManager.cs
index f479e051..e784eaa9 100644
--- a/websocket-sharp/Net/EndPointManager.cs
+++ b/websocket-sharp/Net/EndPointManager.cs
@@ -94,7 +94,7 @@ namespace WebSocketSharp.Net
 
     private static IPAddress convertToAddress (string hostName)
     {
-      if (hostName == "*")
+      if (hostName == "*" || hostName == "+")
         return IPAddress.Any;
 
       IPAddress addr;