diff --git a/websocket-sharp/WebSocket.cs b/websocket-sharp/WebSocket.cs
index 56264c45..105750b2 100644
--- a/websocket-sharp/WebSocket.cs
+++ b/websocket-sharp/WebSocket.cs
@@ -793,23 +793,6 @@ namespace WebSocketSharp
                : _readyState.CheckIfAvailable (connecting, open, closing, closed);
     }
 
-    private bool checkIfAvailable (bool client, bool server, out string message)
-    {
-      message = null;
-
-      if (!client && _client) {
-        message = "This operation isn't available in: client";
-        return false;
-      }
-
-      if (!server && !_client) {
-        message = "This operation isn't available in: server";
-        return false;
-      }
-
-      return true;
-    }
-
     private bool checkIfAvailable (
       bool connecting, bool open, bool closing, bool closed, out string message
     )