diff --git a/electrum/json_db.py b/electrum/json_db.py
index f959740fb..d16031865 100644
--- a/electrum/json_db.py
+++ b/electrum/json_db.py
@@ -25,7 +25,7 @@
 import threading
 import copy
 import json
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Optional
 import jsonpatch
 
 from . import util
@@ -213,7 +213,14 @@ class StoredList(list):
 
 class JsonDB(Logger):
 
-    def __init__(self, s: str, storage=None, encoder=None, upgrader=None):
+    def __init__(
+        self,
+        s: str,
+        *,
+        storage: Optional['WalletStorage'] = None,
+        encoder=None,
+        upgrader=None,
+    ):
         Logger.__init__(self)
         self.lock = threading.RLock()
         self.storage = storage
diff --git a/electrum/wallet_db.py b/electrum/wallet_db.py
index 72f0a7750..c3f190423 100644
--- a/electrum/wallet_db.py
+++ b/electrum/wallet_db.py
@@ -1261,7 +1261,7 @@ class WalletDB(JsonDB):
         storage: Optional['WalletStorage'] = None,
         upgrade: bool = False,
     ):
-        JsonDB.__init__(self, s, storage, encoder=MyEncoder, upgrader=partial(upgrade_wallet_db, do_upgrade=upgrade))
+        JsonDB.__init__(self, s, storage=storage, encoder=MyEncoder, upgrader=partial(upgrade_wallet_db, do_upgrade=upgrade))
         # create pointers
         self.load_transactions()
         # load plugins that are conditional on wallet type