diff --git a/backend/coffre_store.py b/backend/coffre_store.py
index d57d21a..ce9d02b 100644
--- a/backend/coffre_store.py
+++ b/backend/coffre_store.py
@@ -42,6 +42,7 @@ import threading
 import uuid
 from datetime import UTC, datetime, timedelta
 from pathlib import Path
+from typing import Any
 
 from backend.coffre_crypto import (
     decrypt_secret_value,
@@ -306,7 +307,7 @@ def create_coffre(
         data = _load_coffres(base)
         if any(c["slug"] == slug for c in data["coffres"]):
             raise CoffreExisteError(f"Coffre déjà existant : {slug}")
-        coffre = {
+        coffre: dict[str, Any] = {
             "id": str(uuid.uuid4()),
             "slug": slug,
             "nom": nom,