diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 4872bf8d2..823f74ced 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -95,7 +95,7 @@ using namespace libtorrent;
  *****************************************************/
 
 // Constructor
-MainWindow::MainWindow(QWidget *parent, QStringList torrentCmdLine) : QMainWindow(parent), m_posInitialized(false), force_exit(false) {
+MainWindow::MainWindow(QWidget *parent, const QStringList& torrentCmdLine) : QMainWindow(parent), m_posInitialized(false), force_exit(false) {
   setupUi(this);
 
   Preferences pref;
diff --git a/src/mainwindow.h b/src/mainwindow.h
index 8bc106f99..97d8516e8 100644
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -70,7 +70,7 @@ class MainWindow : public QMainWindow, private Ui::MainWindow{
 
 public:
   // Construct / Destruct
-  MainWindow(QWidget *parent=0, QStringList torrentCmdLine=QStringList());
+  MainWindow(QWidget *parent=0, const QStringList& torrentCmdLine = QStringList());
   ~MainWindow();
   // Methods
   QWidget* getCurrentTabWidget() const;