diff --git a/wsme/tests/test_types.py b/wsme/tests/test_types.py
index b67956e..ef432e4 100644
--- a/wsme/tests/test_types.py
+++ b/wsme/tests/test_types.py
@@ -21,7 +21,7 @@ class TestTypes(unittest.TestCase):
 
         My = MyType()
 
-        assert My.validate('a') is None
+        assert My.validate('a') == 'a'
         assert My.tobasetype('a') == 'a'
         assert My.frombasetype('a') == 'a'