diff --git a/include/rqt_image_view/ratio_layouted_frame.h b/include/rqt_image_view/ratio_layouted_frame.h
index 4dc3761..49d534a 100644
--- a/include/rqt_image_view/ratio_layouted_frame.h
+++ b/include/rqt_image_view/ratio_layouted_frame.h
@@ -56,7 +56,7 @@ class RatioLayoutedFrame
 
 public:
 
-  RatioLayoutedFrame(QWidget* parent, Qt::WindowFlags flags = 0);
+  RatioLayoutedFrame(QWidget* parent, Qt::WindowFlags flags = QFlag{0});
 
   virtual ~RatioLayoutedFrame();