diff --git a/src/libslic3r/Model.cpp b/src/libslic3r/Model.cpp
index 6c350e7b4..837f32479 100644
--- a/src/libslic3r/Model.cpp
+++ b/src/libslic3r/Model.cpp
@@ -2405,12 +2405,8 @@ void ModelInstance::transform_polygon(Polygon* polygon) const
 arrangement::ArrangePolygon ModelInstance::get_arrange_polygon() const
 {
 //    static const double SIMPLIFY_TOLERANCE_MM = 0.1;
-    
-    Vec3d rotation = get_rotation();
-    rotation.z()   = 0.;
-    Transform3d trafo_instance = Geometry::assemble_transform(get_offset().z() * Vec3d::UnitZ(), rotation, get_scaling_factor(), get_mirror());
 
-    Polygon p = get_object()->convex_hull_2d(trafo_instance);
+    Polygon p = get_object()->convex_hull_2d(this->get_matrix());
 
 //    if (!p.points.empty()) {
 //        Polygons pp{p};
@@ -2420,12 +2416,24 @@ arrangement::ArrangePolygon ModelInstance::get_arrange_polygon() const
    
     arrangement::ArrangePolygon ret;
     ret.poly.contour = std::move(p);
-    ret.translation  = Vec2crd{scaled(get_offset(X)), scaled(get_offset(Y))};
-    ret.rotation     = get_rotation(Z);
+    ret.translation  = Vec2crd::Zero();
+    ret.rotation     = 0.;
 
     return ret;
 }
 
+void ModelInstance::apply_arrange_result(const Vec2d &offs, double rotation)
+{
+    // write the transformation data into the model instance
+    auto trafo = get_transformation().get_matrix();
+    auto tr = Transform3d::Identity();
+    tr.translate(to_3d(unscaled(offs), 0.));
+    trafo = tr * Eigen::AngleAxisd(rotation, Vec3d::UnitZ()) * trafo;
+    m_transformation.set_matrix(trafo);
+
+    this->object->invalidate_bounding_box();
+}
+
 indexed_triangle_set FacetsAnnotation::get_facets(const ModelVolume& mv, EnforcerBlockerType type) const
 {
     TriangleSelector selector(mv.mesh());
diff --git a/src/libslic3r/Model.hpp b/src/libslic3r/Model.hpp
index 55aceeeb2..ea22b968d 100644
--- a/src/libslic3r/Model.hpp
+++ b/src/libslic3r/Model.hpp
@@ -1167,14 +1167,7 @@ public:
     arrangement::ArrangePolygon get_arrange_polygon() const;
     
     // Apply the arrange result on the ModelInstance
-    void apply_arrange_result(const Vec2d& offs, double rotation)
-    {
-        // write the transformation data into the model instance
-        set_rotation(Z, rotation);
-        set_offset(X, unscale<double>(offs(X)));
-        set_offset(Y, unscale<double>(offs(Y)));
-        this->object->invalidate_bounding_box();
-    }
+    void apply_arrange_result(const Vec2d& offs, double rotation);
 
 protected:
     friend class Print;