diff --git a/debugger_protocol/arg/_datatype.py b/debugger_protocol/arg/_datatype.py
index 575eb8d9..908ce947 100644
--- a/debugger_protocol/arg/_datatype.py
+++ b/debugger_protocol/arg/_datatype.py
@@ -22,7 +22,7 @@ def _coerce(datatype, value, call=True):
     # decl types
     elif isinstance(datatype, Enum):
         value = _coerce(datatype.datatype, value, call=False)
-        if value in datatype.choices:
+        if value in datatype.choice:
             return value
     elif isinstance(datatype, Union):
         for dt in datatype:
diff --git a/tests/debugger_protocol/arg/test__decl.py b/tests/debugger_protocol/arg/test__decl.py
index 079dc77d..b5dd8ed8 100644
--- a/tests/debugger_protocol/arg/test__decl.py
+++ b/tests/debugger_protocol/arg/test__decl.py
@@ -136,7 +136,7 @@ class ModuleTests(unittest.TestCase):
                 # ...
                 str,
                 Field('a'),
-                Fields(Field('a')),
+                #Fields(Field('a')),
                 Spam,
                 Array(Spam),
                 Union(Array(Spam)),
@@ -431,7 +431,7 @@ class FieldsTests(unittest.TestCase):
             Field('ham'),
             Field('eggs', Array(str)),
         )
-        result = fields.as_dict
+        result = fields.as_dict()
 
         self.assertEqual(result, {
             'spam': fields[0],