diff --git a/unwind/models.py b/unwind/models.py
index 8922e5b..030b87e 100644
--- a/unwind/models.py
+++ b/unwind/models.py
@@ -3,6 +3,7 @@ from dataclasses import dataclass, field
 from dataclasses import fields as _fields
 from datetime import datetime, timezone
 from functools import partial
+from types import UnionType
 from typing import (
     Annotated,
     Any,
@@ -52,7 +53,7 @@ def fields(class_or_instance):
 
 def is_optional(tp: Type) -> bool:
     """Return wether the given type is optional."""
-    if get_origin(tp) is not Union:
+    if not isinstance(tp, UnionType) and get_origin(tp) is not Union:
         return False
 
     args = get_args(tp)
@@ -66,7 +67,7 @@ def optional_type(tp: Type) -> Type | None:
     Since they're equivalent this also works for other optioning notations, like
     `Union[int, None]` and `int | None`.
     """
-    if get_origin(tp) is not Union:
+    if not isinstance(tp, UnionType) and get_origin(tp) is not Union:
         return None
 
     args = get_args(tp)
@@ -184,7 +185,8 @@ def validate(o: object) -> None:
         vtype = type(getattr(o, f.name))
         if vtype is not f.type:
             if get_origin(f.type) is vtype or (
-                get_origin(f.type) is Union and vtype in get_args(f.type)
+                (isinstance(f.type, UnionType) or get_origin(f.type) is Union)
+                and vtype in get_args(f.type)
             ):
                 continue
             raise ValueError(f"Invalid value type: {f.name}: {vtype}")