diff --git a/src/core/KeePassApp.cpp b/src/core/KeePassApp.cpp
index 688fc1d2f..557dc2625 100644
--- a/src/core/KeePassApp.cpp
+++ b/src/core/KeePassApp.cpp
@@ -17,12 +17,10 @@
 
 #include "KeePassApp.h"
 
-#include <QtGui/QMessageBox>
 #include <QtGui/QFileOpenEvent>
 
-KeePassApp::KeePassApp(int &argc, char **argv) :
-  QApplication(argc, argv),
-  mainWindow(NULL)
+KeePassApp::KeePassApp(int& argc, char** argv)
+    : QApplication(argc, argv)
 {
 }
 
@@ -30,18 +28,13 @@ KeePassApp::~KeePassApp()
 {
 }
 
-void KeePassApp::setMainWindow(MainWindow *mainWindow)
-{
-  this->mainWindow = mainWindow;
-}
-
 bool KeePassApp::event(QEvent *event)
 {
-  // Handle Apple QFileOpenEvent from finder (double click on .kdbx file)
-  if (event->type() == QEvent::FileOpen && mainWindow) {
-    mainWindow->openDatabase(static_cast<QFileOpenEvent*>(event)->file(), QString(), QString());
-    return true;
-  }
+    // Handle Apple QFileOpenEvent from finder (double click on .kdbx file)
+    if (event->type() == QEvent::FileOpen) {
+        Q_EMIT openDatabase(static_cast<QFileOpenEvent*>(event)->file());
+        return true;
+    }
 
   return (QApplication::event(event));
-}
\ No newline at end of file
+}
diff --git a/src/core/KeePassApp.h b/src/core/KeePassApp.h
index a5242c146..aabd74f64 100644
--- a/src/core/KeePassApp.h
+++ b/src/core/KeePassApp.h
@@ -20,14 +20,14 @@
 
 class KeePassApp : public QApplication
 {
-  Q_OBJECT
-private:
-  MainWindow *mainWindow;
+    Q_OBJECT
 
 public:
-  KeePassApp(int &argc, char **argv);
-  ~KeePassApp();
+    KeePassApp(int& argc, char** argv);
+    ~KeePassApp();
 
-  void setMainWindow(MainWindow *mainWindow);
-  bool event(QEvent *event);
-};
\ No newline at end of file
+    bool event(QEvent *event);
+
+Q_SIGNALS:
+    void openDatabase(const QString& filename);
+};
diff --git a/src/gui/MainWindow.h b/src/gui/MainWindow.h
index e6504c5db..026330d65 100644
--- a/src/gui/MainWindow.h
+++ b/src/gui/MainWindow.h
@@ -33,7 +33,10 @@ class MainWindow : public QMainWindow
 public:
     MainWindow();
     ~MainWindow();
-    void openDatabase(const QString& fileName, const QString& pw, const QString& keyFile);
+
+public Q_SLOTS:
+    void openDatabase(const QString& fileName, const QString& pw = QString(),
+                      const QString& keyFile = QString());
 
 protected:
      void closeEvent(QCloseEvent* event);
diff --git a/src/main.cpp b/src/main.cpp
index 118edd154..a6f3b831c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -51,9 +51,10 @@ int main(int argc, char** argv)
     }
 
     MainWindow mainWindow;
-    app.setMainWindow(&mainWindow);
     mainWindow.show();
 
+    QObject::connect(&app, SIGNAL(openDatabase(QString)), &mainWindow, SLOT(openDatabase(QString)));
+
     if (!filename.isEmpty()) {
         mainWindow.openDatabase(filename, password, QString());
     }