diff --git a/tests/config/types_test.py b/tests/config/types_test.py
index 88c8f067..d915b4f2 100644
--- a/tests/config/types_test.py
+++ b/tests/config/types_test.py
@@ -98,6 +98,11 @@ class StringTest(unittest.TestCase):
         self.assertIsInstance(result, bytes)
         self.assertEqual(b'', result)
 
+    def test_deserialize_enforces_choices_optionnal(self):
+        value = types.String(optional=True, choices=['foo', 'bar', 'baz'])
+        self.assertEqual(None, value.deserialize(b''))
+        self.assertRaises(ValueError, value.deserialize, b'foobar')
+
 
 class SecretTest(unittest.TestCase):
     def test_deserialize_passes_through(self):
@@ -163,6 +168,10 @@ class IntegerTest(unittest.TestCase):
         self.assertEqual(5, value.deserialize('5'))
         self.assertRaises(ValueError, value.deserialize, '15')
 
+    def test_deserialize_respects_optional(self):
+        value = types.Integer(optional=True)
+        self.assertEqual(None, value.deserialize(''))
+
 
 class BooleanTest(unittest.TestCase):
     def test_deserialize_conversion_success(self):