diff --git a/autoresponder_mailing.py b/autoresponder_mailing.py
index 2bfe7e3..03c8d00 100644
--- a/autoresponder_mailing.py
+++ b/autoresponder_mailing.py
@@ -36,7 +36,8 @@ class BitmessageAutoresponder():  # pylint: disable=too-many-locals
                 return
         except KeyError:
             pass
-        self.api.createRandomAddress(base64.b64encode(self.label.encode()))
+        self.api.createRandomAddress(base64.b64encode(
+            self.label.encode()).decode('ascii'))
 
     def loop(self):
         """Main loop"""