diff --git a/json2xml/json2xml.py b/json2xml/json2xml.py
index db101b7..577867b 100644
--- a/json2xml/json2xml.py
+++ b/json2xml/json2xml.py
@@ -42,7 +42,7 @@ def to_xml(self) -> Any | None:
             )
             if self.pretty:
                 try:
-                    result = parseString(xml_data).toprettyxml()
+                    result = parseString(xml_data).toprettyxml(encoding="UTF-8").decode()
                 except ExpatError:
                     raise InvalidDataError
                 return result