diff --git a/src/libslic3r/Format/3mf.cpp b/src/libslic3r/Format/3mf.cpp
index 6356fa17a..f5750162f 100644
--- a/src/libslic3r/Format/3mf.cpp
+++ b/src/libslic3r/Format/3mf.cpp
@@ -1876,7 +1876,7 @@ namespace Slic3r {
             vertices_count += stl.stats.shared_vertices;
 
 #if ENABLE_MODELVOLUME_TRANSFORM
-            Transform3d matrix = volume->get_matrix();
+            const Transform3d& matrix = volume->get_matrix();
 #endif // ENABLE_MODELVOLUME_TRANSFORM
 
             for (int i = 0; i < stl.stats.shared_vertices; ++i)
diff --git a/src/libslic3r/Model.cpp b/src/libslic3r/Model.cpp
index b02153128..07f1b98c1 100644
--- a/src/libslic3r/Model.cpp
+++ b/src/libslic3r/Model.cpp
@@ -512,7 +512,7 @@ void Model::adjust_min_z()
             {
                 coordf_t obj_min_z = obj->bounding_box().min(2);
                 if (obj_min_z < 0.0)
-                    obj->translate(0.0, 0.0, -obj_min_z);
+                    obj->translate_instances(Vec3d(0.0, 0.0, -obj_min_z));
             }
         }
     }