diff --git a/ccv/sheet5/laplacian_pyramid.cpp b/ccv/sheet5/laplacian_pyramid.cpp
index 11555ff..f1b53c0 100644
--- a/ccv/sheet5/laplacian_pyramid.cpp
+++ b/ccv/sheet5/laplacian_pyramid.cpp
@@ -6,6 +6,6 @@ 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(blurred);
+    _layers.push_back(pyramid.get(i) - blurred);
   }
 }