diff --git a/app/models/pydantic/metadata.py b/app/models/pydantic/metadata.py
index 0c71b545..f17d44b6 100644
--- a/app/models/pydantic/metadata.py
+++ b/app/models/pydantic/metadata.py
@@ -177,7 +177,7 @@ class VersionMetadataWithParentResponse(Response):
 
 
 def _date_validator(date_str):
-    if isinstance(date_str, date):
+    if isinstance(date_str, date) or date_str is None:
         return date_str
 
     try: