diff -r 72a8446fdf9a Lib/test/test_os.py
--- a/Lib/test/test_os.py	Mon Mar 18 15:04:33 2013 -0700
+++ b/Lib/test/test_os.py	Tue Mar 19 12:46:41 2013 -0400
@@ -517,11 +517,11 @@
         return os.environ
 
     # Bug 1110478
-    @unittest.skipUnless(os.path.exists('/bin/sh'), 'requires /bin/sh')
     def test_update2(self):
-        os.environ.clear()
+        self.assertTrue('HELLO' not in os.environ)
         os.environ.update(HELLO="World")
-        with os.popen("/bin/sh -c 'echo $HELLO'") as popen:
+        python_cmd = "{0} -c \"import os;print(os.environ['HELLO'])\""
+        with os.popen(python_cmd.format(sys.executable)) as popen:
             value = popen.read().strip()
             self.assertEqual(value, "World")