diff --git a/backend/app/schemas/document.py b/backend/app/schemas/document.py
index 5f775ec..1e592fe 100644
--- a/backend/app/schemas/document.py
+++ b/backend/app/schemas/document.py
@@ -10,7 +10,7 @@ class DocumentResponse(BaseModel):
     file_size: int
     mime_type: str
     file_ext: str
-    sha256: str
+    sha256: str | None
     title: str | None
     description: str | None
     keywords: str | None