diff --git a/dev_requirements/requirements-test.txt b/dev_requirements/requirements-test.txt
index cba85110..2a12e46c 100644
--- a/dev_requirements/requirements-test.txt
+++ b/dev_requirements/requirements-test.txt
@@ -41,9 +41,9 @@ pandas==2.2.2
     # via kohlrahbi (pyproject.toml)
 pluggy==1.5.0
     # via pytest
-pydantic==2.8.1
+pydantic==2.9.1
     # via kohlrahbi (pyproject.toml)
-pydantic-core==2.20.1
+pydantic-core==2.23.3
     # via pydantic
 pytest==8.3.2
     # via
diff --git a/src/kohlrahbi/models/edifact_components.py b/src/kohlrahbi/models/edifact_components.py
index de4d699a..0e3b27bc 100644
--- a/src/kohlrahbi/models/edifact_components.py
+++ b/src/kohlrahbi/models/edifact_components.py
@@ -6,7 +6,7 @@
 import re
 from abc import ABC
 from enum import Enum
-from typing import Callable, Iterable, Literal, Mapping, Optional
+from typing import Callable, Iterable, Literal, Mapping, Optional, Union
 
 from pydantic import BaseModel, Field, StringConstraints, field_validator
 from typing_extensions import Annotated
@@ -238,7 +238,7 @@ class Segment(SegmentLevel):
     A Segment contains multiple data elements.
     """
 
-    data_elements: list[DataElementValuePool | DataElementFreeText] = Field(discriminator="value_type")
+    data_elements: list[Annotated[Union[DataElementValuePool, DataElementFreeText], Field(discriminator="value_type")]]
     section_name: Optional[str] = Field(
         default=None,
         description=(