diff --git a/MainWindow.cpp b/MainWindow.cpp
index 9b95ead..4ad0c44 100644
--- a/MainWindow.cpp
+++ b/MainWindow.cpp
@@ -677,6 +677,7 @@ void MainWindow::createLayout()
   // Output changed -> change destinatioin
   connect(outputWindow->getCanvas(), SIGNAL(shapeChanged(Shape*)),
           destinationCanvas,         SLOT(updateCanvas()));
+
 //  connect(destinationCanvas, SIGNAL(imageChanged()),
 //          sourceCanvas,      SLOT(updateCanvas()));
 
@@ -830,8 +831,13 @@ void MainWindow::createActions()
   displayOutputWindow->setStatusTip(tr("Display output window"));
   displayOutputWindow->setCheckable(true);
   displayOutputWindow->setChecked(true);
+
+  // Manage show/hide of GL output window.
   connect(displayOutputWindow, SIGNAL(toggled(bool)), this, SLOT(toggleOutputWindow(bool)));
 
+  // When closing the GL output window, uncheck the action in menu.
+  connect(outputWindow, SIGNAL(closed()), displayOutputWindow, SLOT(toggle()));
+
 }
 
 void MainWindow::createMenus()
diff --git a/OutputGLWindow.cpp b/OutputGLWindow.cpp
index 71975ab..c3f97a7 100644
--- a/OutputGLWindow.cpp
+++ b/OutputGLWindow.cpp
@@ -35,6 +35,12 @@ OutputGLWindow::OutputGLWindow(QWidget* parent, const QGLWidget * shareWidget) :
   setLayout(layout);
 }
 
+void OutputGLWindow::closeEvent(QCloseEvent *event)
+{
+  emit closed();
+  event->accept();
+}
+
 //void OutputGLWindow::updateCanvas() {
 //  qDebug() << "Update output canvas" << endl;
 //  canvas->updateCanvas();
diff --git a/OutputGLWindow.h b/OutputGLWindow.h
index 6fa1d66..3851861 100644
--- a/OutputGLWindow.h
+++ b/OutputGLWindow.h
@@ -28,11 +28,16 @@
 //since we dont want this window to be closed by the user
 class OutputGLWindow : public QDialog
 {
+  Q_OBJECT
+
 public:
   OutputGLWindow(QWidget* parent = 0, const QGLWidget * shareWidget = 0);
 
 protected:
-  void closeEvent(QCloseEvent *){}
+  void closeEvent(QCloseEvent* event);
+
+signals:
+  void closed();
 
 public:
   DestinationGLCanvas* getCanvas() const { return canvas; }