diff --git a/api/rpk-api/firm/contract/models.py b/api/rpk-api/firm/contract/models.py
index 8dbc94f..401aeb3 100644
--- a/api/rpk-api/firm/contract/models.py
+++ b/api/rpk-api/firm/contract/models.py
@@ -5,6 +5,7 @@ from uuid import UUID
 
 from beanie import PydanticObjectId
 from pydantic import BaseModel, Field
+from pydantic.json_schema import SkipJsonSchema
 
 from firm.core.models import CrudDocument, RichtextSingleline, RichtextMultiline, DictionaryEntry, ForeignKey
 from firm.core.filter import Filter, FilterSchema