diff --git a/websocket-sharp/Net/ClientSslConfiguration.cs b/websocket-sharp/Net/ClientSslConfiguration.cs
index 75056413..523b8e54 100644
--- a/websocket-sharp/Net/ClientSslConfiguration.cs
+++ b/websocket-sharp/Net/ClientSslConfiguration.cs
@@ -58,6 +58,14 @@ namespace WebSocketSharp.Net
 
     #region Public Constructors
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ClientSslConfiguration"/> class.
+    /// </summary>
+    public ClientSslConfiguration ()
+    {
+      _enabledSslProtocols = SslProtocols.Default;
+    }
+
     /// <summary>
     /// Initializes a new instance of the <see cref="ClientSslConfiguration"/> class
     /// with the specified <paramref name="targetHost"/>.