diff --git a/web_widget_open_tab/models/ir_ui_view.py b/web_widget_open_tab/models/ir_ui_view.py
index fdfab6cd3c65..0e980357e6bc 100644
--- a/web_widget_open_tab/models/ir_ui_view.py
+++ b/web_widget_open_tab/models/ir_ui_view.py
@@ -34,5 +34,5 @@ def fields_view_get(
                 tree.insert(name_field[0].getparent().index(name_field[0]) + 1, id_elem)
             else:
                 tree.insert(0, id_elem)
-        res["arch"] = etree.tostring(arch)
+        res["arch"] = etree.tostring(arch, encoding="unicode")
         return res