diff --git a/api/ovdashboard_api/core/calevent.py b/api/ovdashboard_api/core/calevent.py
index f927099..337716c 100644
--- a/api/ovdashboard_api/core/calevent.py
+++ b/api/ovdashboard_api/core/calevent.py
@@ -9,11 +9,11 @@ from functools import total_ordering
 from logging import getLogger
 from typing import Annotated, Self
 
-from pydantic import AfterValidator, BaseModel, ConfigDict
+from pydantic import BaseModel, ConfigDict, StringConstraints
 from vobject.base import Component
 
 _logger = getLogger(__name__)
-StrippedStr = Annotated[str, AfterValidator(lambda s: s.strip())]
+type StrippedStr = Annotated[str, StringConstraints(strip_whitespace=True)]
 
 
 @total_ordering