diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8766c3af6..be0bad0a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fix
 
 - PhysicalObject : Remove to_stl encoding element
+- Schema : Take `None` default value into account
 - WorkflowRun : Compute memory usage, subtract before_memory
 
 
diff --git a/dessia_common/schemas/core.py b/dessia_common/schemas/core.py
index 2e2cd7fe7..b77657743 100644
--- a/dessia_common/schemas/core.py
+++ b/dessia_common/schemas/core.py
@@ -1674,7 +1674,7 @@ def object_default(default_value: CoreDessiaObject = UNDEFINED, class_schema: Cl
 
     Return serialized user default if definition, else None.
     """
-    if default_value is not UNDEFINED:
+    if default_value is not UNDEFINED and default_value is not None:
         return default_value.to_dict(use_pointers=False)
     if class_schema is not None:
         # TODO Should we implement this ? Right now, tests state that the result is None
diff --git a/tests/test_schemas/test_computation_structures.py b/tests/test_schemas/test_computation_structures.py
index 2c4a5d0f9..82f1bf6f7 100644
--- a/tests/test_schemas/test_computation_structures.py
+++ b/tests/test_schemas/test_computation_structures.py
@@ -1,4 +1,6 @@
-from dessia_common.schemas.core import ClassProperty, MethodTypeProperty, AttributeTypeProperty, SchemaAttribute
+from dessia_common.core import DessiaObject
+from dessia_common.schemas.core import ClassProperty, MethodTypeProperty, AttributeTypeProperty, SchemaAttribute, \
+    CustomClass
 from dessia_common.forms import StandaloneObject
 from dessia_common.typings import MethodType, ClassMethodType, AttributeType, ClassAttributeType
 from typing import Type
@@ -8,6 +10,7 @@
 
 
 CUSTOM_CLASS = SchemaAttribute(name="custom_class")
+CUSTOM_CLASS_DEFAULT = SchemaAttribute(name="custom_class", editable=True, title="CustomClass", default_value=None)
 ATTRIBUTE = SchemaAttribute(name="attribute")
 METHOD = SchemaAttribute(name="method")
 
@@ -58,6 +61,19 @@ def test_attributes(self, schema, expected_type, expected_typing, expected_class
         self.assertEqual(computed_schema["properties"]["class_"]["type"], "object")
         self.assertEqual(computed_schema["properties"]["class_"]["python_typing"], expected_class)
 
+    @parameterized.expand([
+        (CustomClass(annotation=DessiaObject, attribute=CUSTOM_CLASS_DEFAULT),
+         "object", "dessia_common.core.DessiaObject"),
+        (CustomClass(annotation=DessiaObject, attribute=CUSTOM_CLASS),
+         "object", "dessia_common.core.DessiaObject")
+    ])
+    def test_custom_classes(self, schema, expected_type, expected_python_typing):
+        computed_schema = schema.to_dict()
+        self.assertEqual(computed_schema["type"], expected_type)
+        self.assertEqual(computed_schema["python_typing"], expected_python_typing)
+        self.assertEqual(computed_schema["title"], schema.attribute.title)
+        self.assertEqual(computed_schema["editable"], schema.attribute.editable)
+
 
 if __name__ == '__main__':
     unittest.main(verbosity=2)