diff --git a/warehouse/oso_dagster/dlt_sources/github_repos/__init__.py b/warehouse/oso_dagster/dlt_sources/github_repos/__init__.py
index f7cbe8310..0f10c2f22 100644
--- a/warehouse/oso_dagster/dlt_sources/github_repos/__init__.py
+++ b/warehouse/oso_dagster/dlt_sources/github_repos/__init__.py
@@ -60,8 +60,8 @@ class Repository(BaseModel):
     license_spdx_id: str
     license_name: str
     language: str
-    created_at: Optional[datetime]
-    updated_at: Optional[datetime]
+    created_at: datetime
+    updated_at: datetime
 
 
 class InvalidGithubURL(Exception):
@@ -131,8 +131,8 @@ def gh_repository_to_repository(
         url=repo.html_url,
         is_fork=repo.fork,
         language=repo.language or "",
-        created_at=repo.created_at or None,
-        updated_at=repo.updated_at or None,
+        created_at=repo.created_at or datetime.fromtimestamp(0),
+        updated_at=repo.updated_at or datetime.fromtimestamp(0),
     )