Index: pyyaml/trunk/tests/lib3/test_input_output.py
===================================================================
--- pyyaml/trunk/tests/lib3/test_input_output.py	(revision 334)
+++ pyyaml/trunk/tests/lib3/test_input_output.py	(revision 336)
@@ -57,4 +57,7 @@
             data2 = stream.getvalue()
             data3 = yaml.dump(value, encoding=encoding, allow_unicode=allow_unicode)
+            if encoding is not None:
+                assert isinstance(data3, bytes)
+                data3 = data3.decode(encoding)
             stream = io.BytesIO()
             if encoding is None: