diff --git a/include/mainwindow.h b/include/mainwindow.h
index 0fde5f4..ea75345 100644
--- a/include/mainwindow.h
+++ b/include/mainwindow.h
@@ -43,6 +43,8 @@ public slots:
     void showMainToolbar(const bool &show = true);
     void showStatusIconToolbar(const bool &show = true);
 
+    // handle changed content at quit
+    void quit();
 
 protected:
 
@@ -52,10 +54,6 @@ protected:
     // show/hide toolbars, otherwise pass on the event to GraphWidget
     void keyPressEvent(QKeyEvent *event);
 
-private slots:
-
-    void quit();
-
 private:
 
     void setUpMainToolbar();
diff --git a/include/systemtray.h b/include/systemtray.h
index 147f7e1..2c4dc66 100644
--- a/include/systemtray.h
+++ b/include/systemtray.h
@@ -14,20 +14,20 @@ class SystemTray : public QWidget
 public:
 
     explicit SystemTray(MainWindow *mainWindow, QWidget *parent = 0);
-    void setup();
-    void show();
 
-private:
+    // access private member
+    void show() { m_systemTrayIcon->show(); }
 
-        MainWindow *m_mainWindow;
+private:
 
-        QSystemTrayIcon *m_systemTrayIcon;
-        QMenu *m_trayIconMenu;
-        QAction *m_minimizeAction;
-        QAction *m_maximizeAction;
-        QAction *m_restoreAction;
-        QAction *m_quitAction;
-        QIcon *m_icon;
+    MainWindow *m_parent;
+    QSystemTrayIcon *m_systemTrayIcon;
+    QMenu *m_trayIconMenu;
+    QAction *m_minimizeAction;
+    QAction *m_maximizeAction;
+    QAction *m_restoreAction;
+    QAction *m_quitAction;
+    QIcon *m_icon;
 
 };
 
diff --git a/src/main.cpp b/src/main.cpp
index 7743bdf..c8752d9 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -37,7 +37,7 @@ int main(int argc, char *argv[])
 
     // system tray?
     MainWindow w;
-    SystemTray systemtray(&w);
+    SystemTray *systemtray;
     if (argParser.isSystemTray() or argParser.isShowMinimized())
     {
         if (!QSystemTrayIcon::isSystemTrayAvailable())
@@ -48,8 +48,8 @@ int main(int argc, char *argv[])
             return EXIT_FAILURE;
         }
         QApplication::setQuitOnLastWindowClosed(false);
-        systemtray.setup();
-        systemtray.show();
+        systemtray = new SystemTray(&w);
+        systemtray->show();
     }
 
     // open file if any
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index b364eeb..42666ad 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -313,6 +313,14 @@ void MainWindow::showStatusIconToolbar(const bool &show)
                                      false);
 }
 
+void MainWindow::quit()
+{
+    if (m_contentChanged && !closeFile())
+        return;
+
+    QApplication::instance()->quit();
+}
+
 void MainWindow::closeEvent(QCloseEvent * event)
 {
     m_contentChanged && !closeFile() ? event->ignore() : event->accept();
@@ -338,15 +346,6 @@ void MainWindow::keyPressEvent(QKeyEvent *event)
     QMainWindow::keyPressEvent(event);
 }
 
-void MainWindow::quit()
-{
-    if (m_contentChanged && !closeFile())
-        return;
-
-    QApplication::instance()->quit();
-}
-
-
 void MainWindow::setUpMainToolbar()
 {
     // why can't I do this with qtcreator? (adding actions to toolbar)
diff --git a/src/systemtray.cpp b/src/systemtray.cpp
index 4968880..5cf23a8 100644
--- a/src/systemtray.cpp
+++ b/src/systemtray.cpp
@@ -2,24 +2,27 @@
 
 #include <QApplication>
 
-void SystemTray::setup()
+
+SystemTray::SystemTray(MainWindow *mainWindow, QWidget *parent)
+    : QWidget(parent),
+      m_parent(mainWindow)
 {
     m_systemTrayIcon = new QSystemTrayIcon(0);
 
     m_minimizeAction = new QAction(tr("Mi&nimize"), m_systemTrayIcon);
-    connect(m_minimizeAction, SIGNAL(triggered()), m_mainWindow,
+    connect(m_minimizeAction, SIGNAL(triggered()), m_parent,
             SLOT(hide()));
 
     m_maximizeAction = new QAction(tr("Ma&ximize"), m_systemTrayIcon);
-    connect(m_maximizeAction, SIGNAL(triggered()), m_mainWindow,
+    connect(m_maximizeAction, SIGNAL(triggered()), m_parent,
             SLOT(showMaximized()));
 
     m_restoreAction = new QAction(tr("&Restore"), m_systemTrayIcon);
-    connect(m_restoreAction, SIGNAL(triggered()), m_mainWindow,
+    connect(m_restoreAction, SIGNAL(triggered()), m_parent,
             SLOT(showNormal()));
 
     m_quitAction = new QAction(tr("&Quit"), m_systemTrayIcon);
-    connect(m_quitAction, SIGNAL(triggered()), qApp,
+    connect(m_quitAction, SIGNAL(triggered()), m_parent,
             SLOT(quit()));
 
     m_trayIconMenu = new QMenu(this);
@@ -34,15 +37,3 @@ void SystemTray::setup()
     m_icon = new QIcon(":/qtmindmap.svg");
     m_systemTrayIcon->setIcon(QIcon(":/qtmindmap.svg"));
 }
-
-SystemTray::SystemTray(MainWindow *mainWindow, QWidget *parent) :
-    QWidget(parent),
-    m_mainWindow(mainWindow)
-{
-}
-
-
-void SystemTray::show()
-{
-    m_systemTrayIcon->show();
-}