diff --git a/src/calibre/utils/mdns.py b/src/calibre/utils/mdns.py
index abf5d57e09..63112036fd 100644
--- a/src/calibre/utils/mdns.py
+++ b/src/calibre/utils/mdns.py
@@ -91,7 +91,7 @@ def create_service(desc, type, port, properties, add_hostname, use_ip_address=No
 
     if add_hostname:
         try:
-            desc += b' (on %s)'%hostname
+            desc += ' (on %s)'%hostname
         except:
             pass