diff --git a/samples/cpp/tutorial_code/ShapeDescriptors/hull_demo.cpp b/samples/cpp/tutorial_code/ShapeDescriptors/hull_demo.cpp
index 7fe5b71f98..e583791d12 100644
--- a/samples/cpp/tutorial_code/ShapeDescriptors/hull_demo.cpp
+++ b/samples/cpp/tutorial_code/ShapeDescriptors/hull_demo.cpp
@@ -49,7 +49,6 @@ int main( int, char** argv )
  */
 void thresh_callback(int, void* )
 {
-  Mat src_copy = src.clone();
   Mat threshold_output;
   vector<vector<Point> > contours;
   vector<Vec4i> hierarchy;