diff --git a/zipline/finance/performance/position.py b/zipline/finance/performance/position.py
index d8acec2c..b23b7ecb 100644
--- a/zipline/finance/performance/position.py
+++ b/zipline/finance/performance/position.py
@@ -33,6 +33,7 @@ Position Tracking
 
 from __future__ import division
 from math import copysign
+from collections import OrderedDict
 
 from copy import copy
 
@@ -228,7 +229,7 @@ last_sale_price: {last_sale_price}"
         self.__dict__.update(state)
 
 
-class positiondict(dict):
+class positiondict(OrderedDict):
 
     def __missing__(self, key):
         pos = Position(key)