diff --git a/src/gui/qt-daemon/application/mainwindow.h b/src/gui/qt-daemon/application/mainwindow.h
index bea8c63f..974b0bea 100644
--- a/src/gui/qt-daemon/application/mainwindow.h
+++ b/src/gui/qt-daemon/application/mainwindow.h
@@ -4,6 +4,7 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#pragma once
 #include <QtWidgets>
 #include <QWebChannel>
 #include <boost/interprocess/ipc/message_queue.hpp>