diff --git a/krfb/main.cpp b/krfb/main.cpp
--- a/krfb/main.cpp
+++ b/krfb/main.cpp
@@ -42,6 +42,16 @@
 
 static bool checkX11Capabilities()
 {
+    if (QApplication::platformName() != QStringLiteral("xcb")) {
+        // XTestQueryExtension segfaults under wayland + XWayland.
+        // exit early and gracefully
+        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 false;
+    }
+
     int bp1, bp2, majorv, minorv;
     Bool r = XTestQueryExtension(QX11Info::display(), &bp1, &bp2,
                                  &majorv, &minorv);