diff --git a/src/slic3r/GUI/GLGizmo.cpp b/src/slic3r/GUI/GLGizmo.cpp
index d45dbf2ed8..7efb8786c6 100644
--- a/src/slic3r/GUI/GLGizmo.cpp
+++ b/src/slic3r/GUI/GLGizmo.cpp
@@ -1511,7 +1511,7 @@ void GLGizmoFlatten::set_flattening_data(const ModelObject* model_object)
     bool object_changed = m_model_object != model_object;
     m_model_object = model_object;
 
-    if (object_changed || is_plane_update_necessary())
+    if (model_object && (object_changed || is_plane_update_necessary()))
         update_planes();
 }