Index: pyyaml/trunk/tests/test_constructor.py
===================================================================
--- pyyaml/trunk/tests/test_constructor.py	(revision 225)
+++ pyyaml/trunk/tests/test_constructor.py	(revision 234)
@@ -289,4 +289,8 @@
                                 (item2 != item2 or (item2 == 0.0 and item2 == 1.0)):
                             continue
+                        if isinstance(item1, datetime.datetime) \
+                                and isinstance(item2, datetime.datetime):
+                            self.failUnlessEqual(item1.microsecond,
+                                    item2.microsecond)
                         if isinstance(item1, datetime.datetime):
                             item1 = item1.utctimetuple()