diff --git a/tests/test_algorithm_gen.py b/tests/test_algorithm_gen.py
index 14a80691..55c3f33a 100644
--- a/tests/test_algorithm_gen.py
+++ b/tests/test_algorithm_gen.py
@@ -47,7 +47,7 @@ class RecordDateSlippage(slippage.FixedSlippage):
         self.latest_date = None
 
     def simulate(self, event, open_orders):
-        self.latest_date = event['datetime']
+        self.latest_date = event.dt
         result = super(RecordDateSlippage, self).simulate(event, open_orders)
         return result
 
diff --git a/zipline/algorithm.py b/zipline/algorithm.py
index eeaedaab..f3b2ab37 100644
--- a/zipline/algorithm.py
+++ b/zipline/algorithm.py
@@ -51,7 +51,6 @@ from zipline.protocol import Event
 from zipline.gens.composites import (
     date_sorted_sources,
     sequential_transforms,
-    alias_dt
 )
 from zipline.gens.tradesimulation import AlgorithmSimulator
 
@@ -263,10 +262,9 @@ class TradingAlgorithm(object):
 
         with_tnfms = sequential_transforms(date_sorted,
                                            *self.transforms)
-        with_alias_dt = alias_dt(with_tnfms)
 
         with_benchmarks = date_sorted_sources(benchmark_return_source,
-                                              with_alias_dt)
+                                              with_tnfms)
 
         # Group together events with the same dt field. This depends on the
         # events already being sorted.
diff --git a/zipline/gens/composites.py b/zipline/gens/composites.py
index 67c3bd66..390c684b 100644
--- a/zipline/gens/composites.py
+++ b/zipline/gens/composites.py
@@ -47,12 +47,3 @@ def sequential_transforms(stream_in, *transforms):
                         stream_in)
 
     return stream_out
-
-
-def alias_dt(stream_in):
-    """
-    Alias the dt field to datetime on each message.
-    """
-    for message in stream_in:
-        message['datetime'] = message['dt']
-        yield message
diff --git a/zipline/protocol.py b/zipline/protocol.py
index 44825d17..91f82d3c 100644
--- a/zipline/protocol.py
+++ b/zipline/protocol.py
@@ -117,6 +117,21 @@ class SIDData(object):
         if initial_values:
             self.__dict__ = initial_values
 
+    @property
+    def datetime(self):
+        """
+        Provides an alias from data['foo'].datetime -> data['foo'].dt
+
+        `datetime` was previously provided by adding a seperate `datetime`
+        member of the SIDData object via a generator that wrapped the incoming
+        data feed and added the field to each equity event.
+
+        This alias is intended to be temporary, to provide backwards
+        compatibility with existing algorithms, but should be considered
+        deprecated, and may be removed in the future.
+        """
+        return self.dt
+
     def __getitem__(self, name):
         return self.__dict__[name]
 
diff --git a/zipline/transforms/batch_transform.py b/zipline/transforms/batch_transform.py
index b7104f80..93d4b2d3 100644
--- a/zipline/transforms/batch_transform.py
+++ b/zipline/transforms/batch_transform.py
@@ -236,7 +236,7 @@ class BatchTransform(object):
         Point of entry. Process an event frame.
         """
         # extract dates
-        dts = [event.datetime for event in itervalues(data._data)]
+        dts = [event.dt for event in itervalues(data._data)]
         # we have to provide the event with a dt. This is only for
         # checking if the event is outside the window or not so a
         # couple of seconds shouldn't matter. We don't add it to
@@ -439,8 +439,7 @@ class BatchTransform(object):
         # with CUSTOM data events, there may be different fields
         # per sid. So the allowable keys are the union of all events.
         union = set.union(*sid_keys)
-        unwanted_fields = set(['portfolio', 'sid', 'dt', 'type',
-                               'datetime', 'source_id'])
+        unwanted_fields = set(['portfolio', 'sid', 'dt', 'type', 'source_id'])
         return union - unwanted_fields
 
     def _get_field_names(self, event):