diff --git a/datev_export_xml/models/datev_xml_generator.py b/datev_export_xml/models/datev_xml_generator.py
index 82ef2647..afd20a31 100644
--- a/datev_export_xml/models/datev_xml_generator.py
+++ b/datev_export_xml/models/datev_xml_generator.py
@@ -83,7 +83,9 @@ def generate_xml_document(self, invoices, check_xsd=True):
                 "Document_v050.xsd",
             )
 
-        return "document.xml", etree.tostring(root)
+        return "document.xml", etree.tostring(
+            root, xml_declaration=True, encoding="UTF-8"
+        )
 
     @api.model
     def generate_xml_invoice(self, invoice, check_xsd=True):
@@ -102,4 +104,4 @@ def generate_xml_invoice(self, invoice, check_xsd=True):
                 invoice=invoice,
             )
 
-        return doc_name, etree.tostring(root)
+        return doc_name, etree.tostring(root, xml_declaration=True, encoding="UTF-8")