diff --git a/slixmpp/plugins/xep_0084/stanza.py b/slixmpp/plugins/xep_0084/stanza.py
index 174a1078..ebcd73e3 100644
--- a/slixmpp/plugins/xep_0084/stanza.py
+++ b/slixmpp/plugins/xep_0084/stanza.py
@@ -21,11 +21,11 @@ class Data(ElementBase):
     def get_value(self):
         if self.xml.text:
             return b64decode(bytes(self.xml.text))
-        return ''
+        return b''
 
     def set_value(self, value):
         if value:
-            self.xml.text = b64encode(bytes(value))
+            self.xml.text = b64encode(bytes(value)).decode()
         else:
             self.xml.text = ''