diff --git a/pyproject.toml b/pyproject.toml
index 8ac855d7..8eab293d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,7 +21,7 @@ greenlet = "^2.0.1"
 inflection = "^0.5.1"
 pandas = "^1.2.4"
 prefect = "^2.7.3"
-pydantic = "^1.10.2"
+pydantic = ">2"
 pytest-asyncio = "^0.20.2"
 pytest-cases = "^3.6.13"
 requests = "^2.25.1"
diff --git a/src/omnipy/data/dataset.py b/src/omnipy/data/dataset.py
index a906fe4d..e61c0fb0 100644
--- a/src/omnipy/data/dataset.py
+++ b/src/omnipy/data/dataset.py
@@ -6,13 +6,14 @@
 
 # from orjson import orjson
 from pydantic import Field, PrivateAttr, ValidationError
-from pydantic.fields import Undefined
+# from pydantic.fields import Undefined
 from pydantic.generics import GenericModel
 from pydantic.utils import lenient_issubclass
 
 from omnipy.data.model import generate_qualname, Model
 
 ModelT = TypeVar('ModelT', bound=Model)
+Undefined = object()
 DATA_KEY = 'data'
 
 # def orjson_dumps(v, *, default):