diff --git a/sleekxmpp/features/feature_mechanisms/stanza/auth.py b/sleekxmpp/features/feature_mechanisms/stanza/auth.py
index 9155adf..d2a981f 100644
--- a/sleekxmpp/features/feature_mechanisms/stanza/auth.py
+++ b/sleekxmpp/features/feature_mechanisms/stanza/auth.py
@@ -43,7 +43,7 @@ class Auth(StanzaBase):
         if not self['mechanism'] in self.plain_mechs:
             self.xml.text = bytes(base64.b64encode(values)).decode('utf-8')
         else:
-            self.xml.text = values
+            self.xml.text = bytes(values).decode('utf-8')
 
     def del_value(self):
         self.xml.text = ''
diff --git a/sleekxmpp/thirdparty/suelta/mechanisms/messenger_oauth2.py b/sleekxmpp/thirdparty/suelta/mechanisms/messenger_oauth2.py
index c72bc0e..f5b0dde 100644
--- a/sleekxmpp/thirdparty/suelta/mechanisms/messenger_oauth2.py
+++ b/sleekxmpp/thirdparty/suelta/mechanisms/messenger_oauth2.py
@@ -1,6 +1,5 @@
-from sleekxmpp.thirdparty.suelta.util import hash, bytes
+from sleekxmpp.thirdparty.suelta.util import bytes
 from sleekxmpp.thirdparty.suelta.sasl import Mechanism, register_mechanism
-from sleekxmpp.thirdparty.suelta.exceptions import SASLError, SASLCancelled
 
 
 class X_MESSENGER_OAUTH2(Mechanism):
@@ -10,7 +9,7 @@ class X_MESSENGER_OAUTH2(Mechanism):
         self.check_values(['access_token'])
 
     def process(self, challenge=None):
-        return self.values['access_token']
+        return bytes(self.values['access_token'])
 
     def okay(self):
         return True