diff --git a/GUI/View/Mask/MaskGraphicsScene.cpp b/GUI/View/Mask/MaskGraphicsScene.cpp
index 7ee84d99cd1c2fbdd69bb64beece3a7ef1a5cb24..52481584cc2a18ba24430033a2c4d8cd3bbb973f 100644
--- a/GUI/View/Mask/MaskGraphicsScene.cpp
+++ b/GUI/View/Mask/MaskGraphicsScene.cpp
@@ -23,8 +23,6 @@
 #include <QGraphicsSceneContextMenuEvent>
 #include <boost/polymorphic_cast.hpp>
 
-using boost::polymorphic_downcast;
-
 namespace {
 
 const QRectF default_scene_rect(0, 0, 800, 600);