diff --git a/bitcoinrpc/authproxy.py b/bitcoinrpc/authproxy.py
index 00de290..b10b078 100644
--- a/bitcoinrpc/authproxy.py
+++ b/bitcoinrpc/authproxy.py
@@ -69,7 +69,7 @@ def __init__(self, service_url, service_name=None, timeout=HTTP_TIMEOUT):
         self.__id_count = 0
         authpair = "%s:%s" % (self.__url.username, self.__url.password)
         authpair = authpair.encode('utf8')
-        self.__auth_header = "Basic %s" % base64.b64encode(authpair)
+        self.__auth_header = "Basic %s" % base64.b64encode(authpair).decode('utf8')
         if self.__url.scheme == 'https':
             self.__conn = httplib.HTTPSConnection(self.__url.hostname, port,
                                                   None, None, False,