diff -r cf0b7d3e5fc6 Lib/test/test_posix.py
--- a/Lib/test/test_posix.py	Wed Feb 20 22:15:47 2013 +0200
+++ b/Lib/test/test_posix.py	Wed Feb 20 23:32:26 2013 +0200
@@ -453,7 +453,7 @@
             check_stat(uid, gid)
             self.assertRaises(OSError, chown_func, first_param, 0, -1)
             check_stat(uid, gid)
-            if gid != 0:
+            if 0 not in os.getgroups():
                 self.assertRaises(OSError, chown_func, first_param, -1, 0)
                 check_stat(uid, gid)
         # test illegal types