diff --git a/src/authentic2_auth_fedict/__init__.py b/src/authentic2_auth_fedict/__init__.py
index bb0fe58..d20ce62 100644
--- a/src/authentic2_auth_fedict/__init__.py
+++ b/src/authentic2_auth_fedict/__init__.py
@@ -74,6 +74,15 @@ class Plugin(object):
     def attribute_kinds(self):
         from . import fields
 
+        def attribute_json_loads(x):
+            if not x:
+                return x
+            try:
+                return json.loads(x)
+            except json.JSONDecodeError:
+                # "compatibility" with native date/phone kinds
+                return x
+
         return [
             {
                 'label': _('National Register Number'),
@@ -85,14 +94,14 @@ class Plugin(object):
             {
                 'label': _('Date'),
                 'serialize': json.dumps,
-                'deserialize': json.loads,
+                'deserialize': attribute_json_loads,
                 'name': 'date',
                 'field_class': fields.DateField,
             },
             {
                 'label': _('Date'),
                 'serialize': json.dumps,
-                'deserialize': json.loads,
+                'deserialize': attribute_json_loads,
                 'name': 'fedict_date',
                 'field_class': fields.DateField,
             },
@@ -113,14 +122,14 @@ class Plugin(object):
             {
                 'label': _('Phone number'),
                 'serialize': json.dumps,
-                'deserialize': json.loads,
+                'deserialize': attribute_json_loads,
                 'name': 'phone',
                 'field_class': fields.NumPhoneField,
             },
             {
                 'label': _('Phone number'),
                 'serialize': json.dumps,
-                'deserialize': json.loads,
+                'deserialize': attribute_json_loads,
                 'name': 'fedict_phone',
                 'field_class': fields.NumPhoneField,
             },