diff --git a/zipline/gens/tradesimulation.py b/zipline/gens/tradesimulation.py
index db72f5bd..8d7c6132 100644
--- a/zipline/gens/tradesimulation.py
+++ b/zipline/gens/tradesimulation.py
@@ -195,7 +195,7 @@ class AlgorithmSimulator(object):
                                     )
                                 self.algo.perf_tracker.handle_intraday_close()
 
-                    self.portfolio_needs_update = True
+                    self.algo.portfolio_needs_update = True
 
             risk_message = self.algo.perf_tracker.handle_simulation_end()
             yield risk_message