diff --git a/tests/run-messenger.cpp b/tests/run-messenger.cpp
index 8cf007d..9f39848 100644
--- a/tests/run-messenger.cpp
+++ b/tests/run-messenger.cpp
@@ -1,84 +1,84 @@
 /* run-messenger.cpp - Test for GpgOL's external windowmessage API.
  * Copyright (C) 2016 by Bundesamt für Sicherheit in der Informationstechnik
  * Software engineering by Intevation GmbH
  *
  * This file is part of GpgOL.
  *
  * GpgOL is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * GpgOL is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 
 #include <windows.h>
 
 #include <stdio.h>
 
 static int
 show_usage (int ex)
 {
   fputs ("usage: run-messgenger id [PAYLOAD]\n\n"
          "Options:\n"
          , stderr);
   exit (ex);
 }
 
 
 int main(int argc, char **argv)
 {
   int last_argc = -1;
   if (argc)
     { argc--; argv++; }
 
   while (argc && last_argc != argc )
     {
       last_argc = argc;
       if (!strcmp (*argv, "--help"))
         {
           show_usage (0);
         }
     }
 
   if (argc != 1 && argc != 2)
     {
       show_usage (1);
     }
 
   int id = atoi (*argv);
 
   HWND gpgol = FindWindowA ("GpgOLResponder", "GpgOLResponder");
 
   if (!gpgol)
     {
       fprintf (stderr, "Failed to find GpgOL Window");
       exit (1);
     }
 
   if (argc == 1)
     {
       printf ("Sending message: %i\n", id);
-      SendMessage (gpgol, WM_USER, id, NULL);
+      SendMessage (gpgol, WM_USER, id, 0);
       exit (0);
     }
 
   /* Send message with payload */
   char *payload = argv[1];
   COPYDATASTRUCT cds;
 
   cds.dwData = id;
   cds.cbData = strlen (payload) + 1;
   cds.lpData = payload;
 
   printf ("Sending message: %i\n with param: %s", id, payload);
   SendMessage (gpgol, WM_COPYDATA, 0, (LPARAM) &cds);
   exit (0);
 }