diff --git a/GraphicsView/demo/Polygon/Polygon_2.cpp b/GraphicsView/demo/Polygon/Polygon_2.cpp
index 6e49bb23736..c9b69b361dd 100644
--- a/GraphicsView/demo/Polygon/Polygon_2.cpp
+++ b/GraphicsView/demo/Polygon/Polygon_2.cpp
@@ -522,6 +522,7 @@ MainWindow::clearMinkowski()
 {
   if(minkgi != 0){
     scene.removeItem(minkgi);
+    delete minkgi;
     minkgi = 0;
   }
 }