diff --git a/app/core/_secrets.py b/app/core/_secrets.py
index 4f6451f..b29ffe7 100644
--- a/app/core/_secrets.py
+++ b/app/core/_secrets.py
@@ -9,6 +9,7 @@ from tonsdk.utils import Address
 from app.core._blockchain.ton.wallet_v3cr3 import WalletV3CR3
 from app.core.logger import make_log
 from sqlalchemy import create_engine, text
+from typing import Optional
 
 
 def _load_seed_from_env_or_generate() -> bytes:
@@ -44,7 +45,7 @@ def _init_seed_via_db() -> bytes:
             if time.time() - start > 120:
                 raise TimeoutError("service_config table not available")
 
-        def read_seed() -> bytes | None:
+        def read_seed() -> Optional[bytes]:
             row = conn.execute(text("SELECT packed_value FROM service_config WHERE key = :k LIMIT 1"), {"k": "private_key"}).first()
             if not row:
                 return None