diff --git a/src/conf.py b/src/conf.py
index b948898ea..ba5cd0699 100644
--- a/src/conf.py
+++ b/src/conf.py
@@ -289,8 +289,7 @@ class SpaceSeparatedSetOfChannels(registry.SpaceSeparatedListOf):
                 channels_with_key.append(channel)
             else:
                 channels.append(channel)
-        return ircmsgs.join(','.join(channels_with_key + channels),
-                ','.join(keys))
+        return ircmsgs.joins(channels_with_key + channels, keys)
 
 def registerNetwork(name, password='', ssl=False, sasl_username='',
         sasl_password=''):
diff --git a/src/ircmsgs.py b/src/ircmsgs.py
index 550cc7faa..d50e5940c 100644
--- a/src/ircmsgs.py
+++ b/src/ircmsgs.py
@@ -615,7 +615,7 @@ def notice(recipient, s, prefix='', msg=None):
 def join(channel, key=None, prefix='', msg=None):
     """Returns a JOIN to a channel"""
     if conf.supybot.protocols.irc.strictRfc():
-        assert areChannels(channel), repr(channel)
+        assert isChannels(channel), repr(channel)
     if msg and not prefix:
         prefix = msg.prefix
     if key is None: