diff --git a/src/tray-menu.hpp b/src/tray-menu.hpp
index 10f45c3..0ffdcb3 100644
--- a/src/tray-menu.hpp
+++ b/src/tray-menu.hpp
@@ -75,10 +75,11 @@
 private:
   QQmlContext* m_context;
   bool m_isNfdRunning;
-  QSystemTrayIcon *tray;
-  QMenu* menu;
-  QAction* pref;
-  QAction* quit;
+  QSystemTrayIcon* m_tray;
+  QMenu* m_menu;
+  QAction* m_entryPref;
+  QAction* m_entrySec;
+  QAction* m_entryQuit;
 };
 
 } // namespace ndn