diff --git a/shadowsocks/asyncdns.py b/shadowsocks/asyncdns.py
index 3273c36..3f92e62 100644
--- a/shadowsocks/asyncdns.py
+++ b/shadowsocks/asyncdns.py
@@ -289,7 +289,7 @@ class DNSResolver(object):
                 for line in content:
                     line = line.strip()
                     if line:
-                        parts = line.split(' ', 1)
+                        parts = line.split(b' ', 1)
                         if len(parts) >= 2:
                             server = parts[0]
                             port = int(parts[1])