diff --git a/zipline/data/data_portal.py b/zipline/data/data_portal.py
index d691fc5b..2cddec7c 100644
--- a/zipline/data/data_portal.py
+++ b/zipline/data/data_portal.py
@@ -32,7 +32,6 @@ BASE_FIELDS = {
 class DataPortal(object):
     def __init__(self,
                  env,
-                 sim_params=None,
                  equity_daily_reader=None,
                  equity_minute_reader=None,
                  future_daily_reader=None,