diff --git a/MainWindow.h b/MainWindow.h
index f0f4640..449bd88 100644
--- a/MainWindow.h
+++ b/MainWindow.h
@@ -284,6 +284,8 @@ public:
   static const int PROPERTY_PANEL_MINIMUM_WIDTH  = 400;
   static const int CANVAS_MINIMUM_WIDTH  = 480;
   static const int CANVAS_MINIMUM_HEIGHT = 270;
+  static const int OUTPUT_WINDOW_MINIMUM_WIDTH = 480;
+  static const int OUTPUT_WINDOW_MINIMUM_HEIGHT = 270;
 };
 
 #endif /* MAIN_WINDOW_H_ */
diff --git a/MapperGLCanvas.cpp b/MapperGLCanvas.cpp
index bfa3a08..8934bf6 100644
--- a/MapperGLCanvas.cpp
+++ b/MapperGLCanvas.cpp
@@ -36,16 +36,17 @@ void MapperGLCanvas::initializeGL()
   //glEnable(GL_CULL_FACE);
 }
 
-void MapperGLCanvas::resizeGL(int /* width */, int /* height */)
+void MapperGLCanvas::resizeGL(int width, int height)
 {
-  glViewport(0, 0, width(), height());
+  qDebug() << "Resize to " << width << "x" << height << endl;
+  glViewport(0, 0, width, height);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glMatrixMode (GL_PROJECTION);
   glLoadIdentity ();
   glOrtho (
-    0.0f, (GLfloat) width(), // left, right
-    (GLfloat) height(), 0.0f, // bottom, top
+    0.0f, (GLfloat) width, // left, right
+    (GLfloat) height, 0.0f, // bottom, top
     -1.0, 1.0f);
   glMatrixMode (GL_MODELVIEW);
 
diff --git a/OutputGLWindow.cpp b/OutputGLWindow.cpp
index 4cd04de..71975ab 100644
--- a/OutputGLWindow.cpp
+++ b/OutputGLWindow.cpp
@@ -23,10 +23,16 @@
 
 OutputGLWindow::OutputGLWindow(QWidget* parent, const QGLWidget * shareWidget) : QDialog(parent)
 {
+  resize(MainWindow::OUTPUT_WINDOW_MINIMUM_WIDTH, MainWindow::OUTPUT_WINDOW_MINIMUM_HEIGHT);
 
   canvas = new DestinationGLCanvas(this, shareWidget);
   canvas->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+  canvas->setMinimumSize(MainWindow::OUTPUT_WINDOW_MINIMUM_WIDTH, MainWindow::OUTPUT_WINDOW_MINIMUM_HEIGHT);
 
+  QLayout* layout = new QVBoxLayout;
+  layout->setContentsMargins(0,0,0,0); // remove margin
+  layout->addWidget(canvas);
+  setLayout(layout);
 }
 
 //void OutputGLWindow::updateCanvas() {