test_support was renamed to support on py3k.
diff --git a/Lib/test/test_posixpath.py b/Lib/test/test_posixpath.py
index 17be3d2..a37be25 100644
--- a/Lib/test/test_posixpath.py
+++ b/Lib/test/test_posixpath.py
@@ -419,7 +419,7 @@
             self.assert_(isinstance(posixpath.expanduser(b"~root/"), bytes))
             self.assert_(isinstance(posixpath.expanduser(b"~foo/"), bytes))
 
-            with test_support.EnvironmentVarGuard() as env:
+            with support.EnvironmentVarGuard() as env:
                 env.set('HOME', '/')
                 self.assertEqual(posixpath.expanduser("~"), "/")