diff --git a/websocket-sharp/WebSocket.cs b/websocket-sharp/WebSocket.cs
index 4cc57631..23a74188 100644
--- a/websocket-sharp/WebSocket.cs
+++ b/websocket-sharp/WebSocket.cs
@@ -669,7 +669,7 @@ namespace WebSocketSharp
         }
 
         if (!_secure) {
-          var msg = "The connection is not secure.";
+          var msg = "This instance does not use a secure connection.";
           throw new InvalidOperationException (msg);
         }