diff --git a/zipline/utils/sentinel.py b/zipline/utils/sentinel.py
index <HASH>..<HASH> 100644
--- a/zipline/utils/sentinel.py
+++ b/zipline/utils/sentinel.py
@@ -13,6 +13,10 @@ class _Sentinel(object):
     __slots__ = ('__weakref__',)
 
 
+def is_sentinel(obj):
+    return isinstance(obj, _Sentinel)
+
+
 def sentinel(name, doc=None):
     try:
         value = sentinel._cache[name]  # memoized
@@ -64,8 +68,4 @@ def sentinel(name, doc=None):
     return Sentinel
 
 
-def is_sentinel(obj):
-    return isinstance(obj, _Sentinel)
-
-
 sentinel._cache = {}
MAINT: Move is_sentinel up to top of file.