diff --git a/src/libslic3r/TriangleMeshSlicer.cpp b/src/libslic3r/TriangleMeshSlicer.cpp
index e27766fb86..ea9eb5ff29 100644
--- a/src/libslic3r/TriangleMeshSlicer.cpp
+++ b/src/libslic3r/TriangleMeshSlicer.cpp
@@ -1075,7 +1075,7 @@ std::vector<Polygons> slice_mesh(
                 auto t = params.trafo;
                 t.prescale(Vec3d(s, s, 1.));
                 auto tf = t.cast<float>();
-                slice_make_lines(mesh.vertices, [tf](const Vec3f &p) { return tf * p; }, mesh.indices, facets_edges, zs, throw_on_cancel);
+                lines = slice_make_lines(mesh.vertices, [tf](const Vec3f &p) { return tf * p; }, mesh.indices, facets_edges, zs, throw_on_cancel);
             }
         } else {
             // Copy and scale vertices in XY, don't scale in Z.