diff --git a/nouri/main.py b/nouri/main.py
index 38db488..79431e0 100644
--- a/nouri/main.py
+++ b/nouri/main.py
@@ -9,7 +9,6 @@ import sqlite3
 
 from flask import (
     Blueprint,
-    after_this_request,
     current_app,
     flash,
     g,
@@ -3710,18 +3709,17 @@ def backup_export():
         current_app.config["APP_VERSION"],
     )
 
-    @after_this_request
-    def cleanup_backup(response):
-        Path(archive_path).unlink(missing_ok=True)
-        return response
-
-    return send_file(
+    archive_size = Path(archive_path).stat().st_size
+    response = send_file(
         archive_path,
         as_attachment=True,
         download_name=download_name,
         mimetype="application/zip",
         max_age=0,
     )
+    response.content_length = archive_size
+    response.call_on_close(lambda: Path(archive_path).unlink(missing_ok=True))
+    return response
 
 
 @main_bp.post("/settings/backup/restore")