diff --git a/backend/app/api/office.py b/backend/app/api/office.py
index f2e02a1..f619263 100644
--- a/backend/app/api/office.py
+++ b/backend/app/api/office.py
@@ -365,7 +365,7 @@ def onlyoffice_config(file_id):
         'config': {
             'document': {
                 'fileType': ext,
-                'key': f'{file_id}_{f.checksum or "0"}_{callback_key[:8]}',
+                'key': f'{file_id}_{int(datetime.now(timezone.utc).timestamp())}_{callback_key[:8]}',
                 'title': f.name,
                 'url': f'{internal_url}/api/files/oo-download/{file_access_key}',
             },