diff --git a/TLSharp.Core/Network/MtProtoSender.cs b/TLSharp.Core/Network/MtProtoSender.cs
index 5ba75b3..4bc8e84 100644
--- a/TLSharp.Core/Network/MtProtoSender.cs
+++ b/TLSharp.Core/Network/MtProtoSender.cs
@@ -18,10 +18,10 @@ namespace TLSharp.Core.Network
     {
         //private ulong sessionId = GenerateRandomUlong();
 
-        private TcpTransport _transport;
-        private Session _session;
+        private readonly TcpTransport _transport;
+        private readonly Session _session;
 
-        public List<ulong> needConfirmation = new List<ulong>();
+        public readonly List<ulong> needConfirmation = new List<ulong>();
 
         public MtProtoSender(TcpTransport transport, Session session)
         {