diff --git a/krfb/main.cpp b/krfb/main.cpp
index 2d24771..0b92eab 100644
--- a/krfb/main.cpp
+++ b/krfb/main.cpp
@@ -1,152 +1,160 @@
 /***************************************************************************
                                    main.cpp
                              -------------------
     begin                : Sat Dec  8 03:23:02 CET 2001
     copyright            : (C) 2001-2003 by Tim Jansen
     email                : tim@tjansen.de
  ***************************************************************************/
 
 /***************************************************************************
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 2 of the License, or     *
  *   (at your option) any later version.                                   *
  *                                                                         *
  ***************************************************************************/
 
 #include "mainwindow.h"
 #include "trayicon.h"
 #include "invitationsrfbserver.h"
 #include "krfbconfig.h"
 #include "krfb_version.h"
 
 #include <KAboutData>
 #include <KDBusService>
 #include <KLocalizedString>
 #include <KMessageBox>
 
 #include <QDebug>
 #include <QPixmap>
 #include <qwindowdefs.h>
 #include <QX11Info>
 
 #include <signal.h>
 #include <X11/extensions/XTest.h>
 #include <QCommandLineParser>
 #include <QCommandLineOption>
 
 
 static const char description[] = I18N_NOOP("VNC-compatible server to share "
                                   "desktops");
 
 static bool checkX11Capabilities()
 {
     int bp1, bp2, majorv, minorv;
     Bool r = XTestQueryExtension(QX11Info::display(), &bp1, &bp2,
                                  &majorv, &minorv);
 
     if ((!r) || (((majorv * 1000) + minorv) < 2002)) {
         KMessageBox::error(nullptr,
                            i18n("Your X11 Server does not support the required XTest extension "
                                 "version 2.2. Sharing your desktop is not possible."),
                            i18n("Desktop Sharing Error"));
         return false;
     }
 
     return true;
 }
 
 
 static void checkOldX11PluginConfig() {
     if (KrfbConfig::preferredFrameBufferPlugin() == QStringLiteral("x11")) {
         qDebug() << "Detected deprecated configuration: preferredFrameBufferPlugin = x11";
         KConfigSkeletonItem *config_item = KrfbConfig::self()->findItem(
                     QStringLiteral("preferredFrameBufferPlugin"));
         if (config_item) {
             config_item->setProperty(QStringLiteral("xcb"));
             KrfbConfig::self()->save();
             qDebug() << "  Fixed preferredFrameBufferPlugin from x11 to xcb.";
         }
     }
 }
 
 
 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
 
     KLocalizedString::setApplicationDomain("krfb");
 
     KAboutData aboutData(QStringLiteral("krfb"),
                          i18n("Desktop Sharing"),
                          QStringLiteral(KRFB_VERSION_STRING),
                          i18n(description),
                          KAboutLicense::GPL,
                          i18n("(c) 2009-2010, Collabora Ltd.\n"
                                "(c) 2007, Alessandro Praduroux\n"
                                "(c) 2001-2003, Tim Jansen\n"
                                "(c) 2001, Johannes E. Schindelin\n"
                                "(c) 2000-2001, Const Kaplinsky\n"
                                "(c) 2000, Tridia Corporation\n"
                                "(c) 1999, AT&T Laboratories Boston\n"));
     aboutData.addAuthor(i18n("George Goldberg"),
                         i18n("Telepathy tubes support"),
                         QStringLiteral("george.goldberg@collabora.co.uk"));
     aboutData.addAuthor(i18n("George Kiagiadakis"),
                         QString(),
                         QStringLiteral("george.kiagiadakis@collabora.co.uk"));
     aboutData.addAuthor(i18n("Alessandro Praduroux"), i18n("KDE4 porting"), QStringLiteral("pradu@pradu.it"));
     aboutData.addAuthor(i18n("Tim Jansen"), i18n("Original author"), QStringLiteral("tim@tjansen.de"));
     aboutData.addCredit(i18n("Johannes E. Schindelin"),
                         i18n("libvncserver"));
     aboutData.addCredit(i18n("Const Kaplinsky"),
                         i18n("TightVNC encoder"));
     aboutData.addCredit(i18n("Tridia Corporation"),
                         i18n("ZLib encoder"));
     aboutData.addCredit(i18n("AT&T Laboratories Boston"),
                         i18n("original VNC encoders and "
                               "protocol design"));
     KAboutData::setApplicationData(aboutData);
 
     QCommandLineParser parser;
     aboutData.setupCommandLine(&parser);
     const QCommandLineOption nodialogOption(QStringList{ QStringLiteral("nodialog") }, i18n("Do not show the invitations management dialog at startup"));
     parser.addOption(nodialogOption);
 
     parser.process(app);
     aboutData.processCommandLine(&parser);
 
     KDBusService service(KDBusService::Unique, &app);
 
     app.setQuitOnLastWindowClosed(false);
 
-    if (!checkX11Capabilities()) {
+    if (QX11Info::isPlatformX11()) {
+        if (!checkX11Capabilities()) {
+            return 1;
+        }
+
+        // upgrade the configuration
+        checkOldX11PluginConfig();
+    } else {
+        KMessageBox::error(nullptr,
+                           i18n("Desktop Sharing is not running under an X11 Server. "
+                                "Other display servers are currently not supported."),
+                           i18n("Desktop Sharing Error"));
         return 1;
     }
 
-    // upgrade the configuration
-    checkOldX11PluginConfig();
-
     //init the core
     InvitationsRfbServer::init();
 
     //init the GUI
     MainWindow mainWindow;
     TrayIcon trayicon(&mainWindow);
 
     if (KrfbConfig::startMinimized()) {
       mainWindow.hide();
     } else if (app.isSessionRestored() && KMainWindow::canBeRestored(1)) {
         mainWindow.restore(1, false);
     } else if (!parser.isSet(nodialogOption)) {
         mainWindow.show();
     }
 
     sigset_t sigs;
     sigemptyset(&sigs);
     sigaddset(&sigs, SIGPIPE);
     sigprocmask(SIG_BLOCK, &sigs, nullptr);
 
     return app.exec();
 }