diff --git a/Lib/test/test_datetime.py b/Lib/test/test_datetime.py
index 7d503e0..0b9597a 100644
--- a/Lib/test/test_datetime.py
+++ b/Lib/test/test_datetime.py
@@ -2266,7 +2266,7 @@
         # Try with and without naming the keyword.
         off42 = FixedOffset(42, "42")
         another = meth(ts, off42)
-        again = meth(ts, tzinfo=off42)
+        again = meth(ts, tz=off42)
         self.failUnless(another.tzinfo is again.tzinfo)
         self.assertEqual(another.utcoffset(), timedelta(minutes=42))
         # Bad argument with and w/o naming the keyword.
@@ -2279,6 +2279,20 @@
         # Too few args.
         self.assertRaises(TypeError, meth)
 
+        # Try to make sure tz= actually does some conversion.
+        timestamp = 1000000000  #  2001-09-09 01:46:40 UTC, give or take
+        utc = FixedOffset(0, "utc", 0)
+        expected = datetime(2001, 9, 9, 1, 46, 40)
+        got = datetime.utcfromtimestamp(timestamp)
+        # We don't support leap seconds, but maybe the platfrom insists
+        # on using them, so don't demand exact equality).
+        self.failUnless(abs(got - expected) < timedelta(minutes=1))
+
+        est = FixedOffset(-5*60, "est", 0)
+        expected -= timedelta(hours=5)
+        got = datetime.fromtimestamp(timestamp, est).replace(tzinfo=None)
+        self.failUnless(abs(got - expected) < timedelta(minutes=1))
+
     def test_tzinfo_utcnow(self):
         meth = self.theclass.utcnow
         # Ensure it doesn't require tzinfo (i.e., that this doesn't blow up).