diff --git a/zipline/gens/utils.py b/zipline/gens/utils.py
index 585f5ce1..9bd8f2c5 100644
--- a/zipline/gens/utils.py
+++ b/zipline/gens/utils.py
@@ -39,7 +39,6 @@ def hash_args(*args, **kwargs):
 def assert_datasource_protocol(event):
     """Assert that an event meets the protocol for datasource outputs."""
 
-    assert isinstance(event.source_id, basestring)
     assert event.type in DATASOURCE_TYPE
 
     # Done packets have no dt.
@@ -61,17 +60,14 @@ def assert_trade_protocol(event):
 
 def assert_datasource_unframe_protocol(event):
     """Assert that an event is valid output of zp.DATASOURCE_UNFRAME."""
-    assert isinstance(event.source_id, basestring)
     assert event.type in DATASOURCE_TYPE
 
 
 def assert_sort_protocol(event):
     """Assert that an event is valid input to zp.FEED_FRAME."""
-    assert isinstance(event.source_id, basestring)
     assert event.type in DATASOURCE_TYPE
 
 
 def assert_sort_unframe_protocol(event):
     """Same as above."""
-    assert isinstance(event.source_id, basestring)
     assert event.type in DATASOURCE_TYPE
diff --git a/zipline/transforms/utils.py b/zipline/transforms/utils.py
index 8f6d6801..bccff29d 100644
--- a/zipline/transforms/utils.py
+++ b/zipline/transforms/utils.py
@@ -17,7 +17,6 @@
 """
 Generator versions of transforms.
 """
-import types
 import logbook
 
 
@@ -92,8 +91,6 @@ class StatefulTransform(object):
     Otherwise only dt, tnfm_id, and tnfm_value are forwarded.
     """
     def __init__(self, tnfm_class, *args, **kwargs):
-        assert isinstance(tnfm_class, (types.ObjectType, types.ClassType)), \
-            "Stateful transform requires a class."
         assert hasattr(tnfm_class, 'update'), \
             "Stateful transform requires the class to have an update method"