diff --git a/lib/coins.py b/lib/coins.py
index 2d88b0e..11e4f04 100644
--- a/lib/coins.py
+++ b/lib/coins.py
@@ -70,7 +70,7 @@ class Coin(object):
         match = cls.RPC_URL_REGEX.match(url)
         if not match:
             raise CoinError('invalid daemon URL: "{}"'.format(url))
-        if match.groups()[0] is None:
+        if match.groups()[1] is None:
             url += ':{:d}'.format(cls.RPC_PORT)
         if not url.startswith('http://'):
             url = 'http://' + url