diff --git a/ccv/saliency/laplacian_pyramid.cpp b/ccv/saliency/laplacian_pyramid.cpp
index 8e13f66..c5f92df 100644
--- a/ccv/saliency/laplacian_pyramid.cpp
+++ b/ccv/saliency/laplacian_pyramid.cpp
@@ -6,7 +6,8 @@ laplacian_pyramid::laplacian_pyramid(const gauss_pyramid &pyramid, float sigma)
   for (int i = 0; i < number_of_layers; i++) {
     cv::Mat blurred;
     cv::GaussianBlur(pyramid.get(i), blurred, cv::Size(), sigma, sigma, cv::BORDER_CONSTANT);
-    _layers.push_back(pyramid.get(i) - blurred);
+    cv::Mat laplacian = pyramid.get(i) - blurred;
+    _layers.push_back(laplacian.clone());
   }
 }