diff --git a/zipline/data/data_portal.py b/zipline/data/data_portal.py
index 84c53c05..f8598c38 100644
--- a/zipline/data/data_portal.py
+++ b/zipline/data/data_portal.py
@@ -1090,10 +1090,6 @@ class DataPortal(object):
 
         return data
 
-    @remember_last
-    def _get_market_minutes_for_day(self, end_date):
-        return self.env.market_minutes_for_day(pd.Timestamp(end_date))
-
     def _get_history_daily_window_equities(
             self, assets, days_for_window, end_dt, field_to_use):
         ends_at_midnight = end_dt.hour == 0 and end_dt.minute == 0