diff --git a/krfb/main.cpp b/krfb/main.cpp
--- a/krfb/main.cpp
+++ b/krfb/main.cpp
@@ -42,6 +42,17 @@
 
 static bool checkX11Capabilities()
 {
+    // QX11Info::display() can still be non-null in wayland, if XWayland is running.
+    if (!QX11Info::display() || (QApplication::platformName() != QStringLiteral("xcb"))) {
+        // XTestQueryExtension segfaults under wayland + XWayland.
+        // exit early and gracefully
+        KMessageBox::error(nullptr,
+                           i18n("It seems you are not running X11. "
+                                "Wayland is currently not supported yet!"),
+                           i18n("Desktop Sharing Error"));
+        return false;
+    }
+
     int bp1, bp2, majorv, minorv;
     Bool r = XTestQueryExtension(QX11Info::display(), &bp1, &bp2,
                                  &majorv, &minorv);