diff --git a/plugins/UFPWriter/UFPWriter.py b/plugins/UFPWriter/UFPWriter.py
index 49a6a36d68..d838aaef36 100644
--- a/plugins/UFPWriter/UFPWriter.py
+++ b/plugins/UFPWriter/UFPWriter.py
@@ -90,7 +90,7 @@ class UFPWriter(MeshWriter):
                 Logger.log("e", "Cannot find material container with root id [%s]", material_root_id)
                 return False
 
-            material_container = material_group.root_material_node
+            material_container = material_group.root_material_node.getContainer()
             try:
                 serialized_material = material_container.serialize()
             except NotImplementedError: