diff --git a/SMBLibrary/Client/SMB1FileStore.cs b/SMBLibrary/Client/SMB1FileStore.cs
index 6ac04ab..e7b8b88 100644
--- a/SMBLibrary/Client/SMB1FileStore.cs
+++ b/SMBLibrary/Client/SMB1FileStore.cs
@@ -1,4 +1,4 @@
-/* Copyright (C) 2014-2023 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+/* Copyright (C) 2014-2024 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
  * 
  * You can redistribute this program and/or modify it under the terms of
  * the GNU Lesser Public License as published by the Free Software Foundation,
@@ -181,7 +181,11 @@ namespace SMBLibrary.Client
 
                         TrySendMessage(request);
                         reply = m_client.WaitForMessage(CommandName.SMB_COM_TRANSACTION2);
-                        if (reply.Header.Status == NTStatus.STATUS_SUCCESS && reply.Commands[0] is Transaction2Response)
+                        if (reply == null)
+                        {
+                            return NTStatus.STATUS_INVALID_SMB;
+                        }
+                        else if (reply.Header.Status == NTStatus.STATUS_SUCCESS && reply.Commands[0] is Transaction2Response)
                         {
                             response = (Transaction2Response)reply.Commands[0];
                             Transaction2FindNext2Response nextSubcommandResponse = new Transaction2FindNext2Response(response.TransParameters, response.TransData, reply.Header.UnicodeFlag);
diff --git a/SMBLibrary/Client/SMB2FileStore.cs b/SMBLibrary/Client/SMB2FileStore.cs
index 563514c..81aeec1 100644
--- a/SMBLibrary/Client/SMB2FileStore.cs
+++ b/SMBLibrary/Client/SMB2FileStore.cs
@@ -1,4 +1,4 @@
-/* Copyright (C) 2017-2023 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+/* Copyright (C) 2017-2024 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
  * 
  * You can redistribute this program and/or modify it under the terms of
  * the GNU Lesser Public License as published by the Free Software Foundation,
@@ -165,6 +165,10 @@ namespace SMBLibrary.Client
                     request.Reopen = false;
                     TrySendCommand(request);
                     response = m_client.WaitForCommand(request.MessageID);
+                    if (response == null)
+                    {
+                        return NTStatus.STATUS_INVALID_SMB;
+                    }
                 }
                 return response.Header.Status;
             }