diff --git a/api/libs/helper.py b/api/libs/helper.py
index ba02fe1f5d..888a99fb5c 100644
--- a/api/libs/helper.py
+++ b/api/libs/helper.py
@@ -11,6 +11,7 @@ from collections.abc import Generator, Mapping
 from datetime import datetime
 from hashlib import sha256
 from typing import TYPE_CHECKING, Annotated, Any, Optional, Union, cast
+from uuid import UUID
 from zoneinfo import available_timezones
 
 from flask import Response, stream_with_context
@@ -119,7 +120,17 @@ def uuid_value(value: Any) -> str:
         raise ValueError(error)
 
 
-UUIDStrOrEmpty = Annotated[str, AfterValidator(uuid_value)]
+def normalize_uuid(value: str | UUID | None) -> str | None:
+    if not value:
+        return None
+
+    try:
+        return uuid_value(value)
+    except ValueError as exc:
+        raise ValueError("must be a valid UUID") from exc
+
+
+UUIDStrOrEmpty = Annotated[str, AfterValidator(normalize_uuid)]
 
 
 def alphanumeric(value: str):