diff --git a/Box.hpp b/Box.hpp
index 56cc34d..0a99a33 100644
--- a/Box.hpp
+++ b/Box.hpp
@@ -58,6 +58,11 @@ class BoundingBox {
         lower_ = min(lower_, p);
         upper_ = max(upper_, p);
     }
+
+    void extend(const BoundingBox& b) {
+        extend(b.lower());
+        extend(b.upper());
+    }
 };
 
 using Box3f = BoundingBox<Vec3f>;
diff --git a/Refinement.hpp b/Refinement.hpp
index d0d5d47..0f5b1d2 100644
--- a/Refinement.hpp
+++ b/Refinement.hpp
@@ -39,7 +39,6 @@ void laplacianSmoothing(TriangleMesh<Vec>& mesh, bool preserveBoundary = true, f
                     ++neighCnt;
                 }
                 if (neighCnt > 0) {
-                    float norm = 1.; // (1. + )
                     biharmonic[v1] = -delta / neighCnt + laplacian[v1];
                 }
             });