diff --git a/plugins/UFPWriter/UFPWriter.py b/plugins/UFPWriter/UFPWriter.py
index feaf049db8..c3da529a98 100644
--- a/plugins/UFPWriter/UFPWriter.py
+++ b/plugins/UFPWriter/UFPWriter.py
@@ -31,4 +31,5 @@ class UFPWriter(MeshWriter):
         thumbnail.close()
         archive.addRelation(virtual_path = "/Metadata/thumbnail.png", relation_type = "http://schemas.openxmlformats.org/package/2006/relationships/metadata/thumbnail")
 
-        archive.close()
\ No newline at end of file
+        archive.close()
+        return True
\ No newline at end of file