diff --git a/src/datasource_django/forestadmin/datasource_django/utils/model_introspection.py b/src/datasource_django/forestadmin/datasource_django/utils/model_introspection.py
index 8b44e9ab0..1ec6bcf6e 100644
--- a/src/datasource_django/forestadmin/datasource_django/utils/model_introspection.py
+++ b/src/datasource_django/forestadmin/datasource_django/utils/model_introspection.py
@@ -35,11 +35,19 @@
     GeneratedField = None
 
 
+def serialize_enum_value(value):
+    try:
+        json.dumps(value)
+    except TypeError:
+        value = str(value)
+    return value
+
+
 class FieldFactory:
     @staticmethod
     def _build_enum_values(field: Field) -> Optional[List[str]]:
         if field.choices:
-            return [c[0] for c in field.choices]  # type: ignore
+            return [serialize_enum_value(c[0]) for c in field.choices]  # type: ignore
         return None
 
     @staticmethod
diff --git a/src/datasource_django/tests/utils/test_django_model_introspection.py b/src/datasource_django/tests/utils/test_django_model_introspection.py
index f72c30768..e04852d8c 100644
--- a/src/datasource_django/tests/utils/test_django_model_introspection.py
+++ b/src/datasource_django/tests/utils/test_django_model_introspection.py
@@ -1,3 +1,4 @@
+from datetime import datetime
 from unittest import TestCase
 from unittest.mock import patch
 
@@ -52,6 +53,20 @@ def test_build_should_handle_enums(self):
         self.assertEqual(field_schema["enum_values"], [1, 2, 3])
         self.assertEqual(field_schema["column_type"], PrimitiveType.ENUM)
 
+    def test_build_should_use_str_on_enum_values_when_value_is_not_json_serializable(self):
+        """enums"""
+        now = datetime.now()
+        choices = [
+            (datetime(1916, 1, 1, 1, 1, 1), "WW1"),
+            (datetime(1941, 2, 2, 2, 2, 2), "WW2"),
+            (now, "NOW"),
+        ]
+        field = models.DateField(choices=choices)
+        field_schema = FieldFactory.build(field)
+
+        self.assertEqual(field_schema["enum_values"], ["1916-01-01 01:01:01", "1941-02-02 02:02:02", str(now)])
+        self.assertEqual(field_schema["column_type"], PrimitiveType.ENUM)
+
     def test_build_should_handle_read_only_for_auto_increment_pk(self):
         """readonly"""
         field = models.AutoField(primary_key=True)
diff --git a/src/datasource_toolkit/forestadmin/datasource_toolkit/validations/condition_tree.py b/src/datasource_toolkit/forestadmin/datasource_toolkit/validations/condition_tree.py
index 258955e7e..38559e475 100644
--- a/src/datasource_toolkit/forestadmin/datasource_toolkit/validations/condition_tree.py
+++ b/src/datasource_toolkit/forestadmin/datasource_toolkit/validations/condition_tree.py
@@ -80,7 +80,7 @@ def validate_value_for_operator(condition_tree: ConditionTreeLeaf, column_schema
 
         error_msg = (
             f'The given value attribute "{value}" (type: {value_type}) has an unexpected value '
-            'for the given operator "{condition_tree.operator}."'
+            f'for the given operator "{condition_tree.operator}."'
         )
         allowed_types = MAP_ALLOWED_TYPES_FOR_OPERATOR.get(condition_tree.operator, [])
         if not allowed_types: