diff --git a/bt5/erp5_base/ModuleComponentTemplateItem/portal_components/module.erp5.ImageUtil.py b/bt5/erp5_base/ModuleComponentTemplateItem/portal_components/module.erp5.ImageUtil.py
index ec26c8d52b065e914bdd96f05119a43276632719..59a2916c25c3de285aae57f0c6cf57c6d92c527a 100644
--- a/bt5/erp5_base/ModuleComponentTemplateItem/portal_components/module.erp5.ImageUtil.py
+++ b/bt5/erp5_base/ModuleComponentTemplateItem/portal_components/module.erp5.ImageUtil.py
@@ -65,6 +65,10 @@ def transformUrlToDataURI(content):
     if url_value.startswith("http"):
       image.set(xlink_href, getDataURI(image.get(xlink_href)))
 
-  return """<?xml version="1.0" encoding="UTF-8" standalone="no"?>\n""" + \
-         etree.tostring(root)
+  return etree.tostring(
+    root,
+    encoding="utf-8",
+    xml_declaration=True,
+    standalone="no",
+  )