diff --git a/src/curvature.h b/src/curvature.h
index 84bc771..71dff56 100644
--- a/src/curvature.h
+++ b/src/curvature.h
@@ -14,7 +14,10 @@ public:
     OpenMesh::VPropHandleT<double> vprop_H;
 	OpenMesh::VPropHandleT<QuadPatch> vprop_quad;
 
-	Courbures(MyMesh &mesh) : _mesh(mesh) {}
+	Courbures(MyMesh &mesh) : _mesh(mesh) {
+		_mesh.request_vertex_normals();
+		_mesh.update_normals();
+	}
 
     void set_fixed_colors();
     void normales_locales();