diff --git a/ops.py b/ops.py
index 30a5513..ec919be 100644
--- a/ops.py
+++ b/ops.py
@@ -27,20 +27,10 @@
 
 log = logging.getLogger('ops')
 type_ = type
-darwin = sys.platform == 'darwin'
 
 class Error(Exception): pass
 class ValidationError(Error): pass
 
-def _uid_gid(path, uid, gid):
-    if uid == -1 or gid == -1:
-        st = stat(path)
-        if uid == -1:
-            uid = st.st_uid
-        if gid == -1:
-            gid = st.st_gid
-    return uid, gid
-
 def _chmod(path, value=None):
     try:
         os.chmod(path, value.numeric)
@@ -80,8 +70,12 @@ def _chown(path, uid=-1, gid=-1):
         log.error('chown: invalid uid or gid: %s' % path)
         return False
     # hack around Apple's broken patch (http://bugs.python.org/issue13315)
-    if darwin:
-        uid, gid = _uid_gid(path, uid, gid)
+    if sys.platform == 'darwin' and uid == -1 or gid == -1:
+        st = stat(path)
+        if uid == -1:
+            uid = st.st_uid
+        if gid == -1:
+            gid = st.st_gid
     try:
         os.chown(path, uid, gid)
         return True