diff --git a/electrum/lnworker.py b/electrum/lnworker.py
index 2ef4f19d4..b4a1317fe 100644
--- a/electrum/lnworker.py
+++ b/electrum/lnworker.py
@@ -11,7 +11,7 @@ import operator
 import enum
 from enum import IntEnum, Enum
 from typing import (Optional, Sequence, Tuple, List, Set, Dict, TYPE_CHECKING,
-                    NamedTuple, Union, Mapping, Any, Iterable, AsyncGenerator, DefaultDict, Callable)
+                    NamedTuple, Union, Mapping, Any, Iterable, AsyncGenerator, DefaultDict, Callable, Awaitable)
 import threading
 import socket
 import aiohttp
@@ -842,8 +842,8 @@ class LNWallet(LNWorker):
         self.final_onion_forwarding_failures = {} # todo: should be persisted
         # map forwarded htlcs (fw_info=(scid_hex, htlc_id)) to originating peer pubkeys
         self.downstream_htlc_to_upstream_peer_map = {}  # type: Dict[Tuple[str, int], bytes]
-        # payment_hash -> callback, timeout:
-        self.hold_invoice_callbacks = {}                # type: Dict[bytes, Tuple[Callable[[bytes], None], int]]
+        # payment_hash -> callback:
+        self.hold_invoice_callbacks = {}                # type: Dict[bytes, Callable[[bytes], Awaitable[None]]]
         self.payment_bundles = []                       # lists of hashes. todo:persist
         self.swap_manager = SwapManager(wallet=self.wallet, lnworker=self)
 
@@ -2070,7 +2070,7 @@ class LNWallet(LNWorker):
         info = PaymentInfo(payment_hash, lightning_amount_sat * 1000, RECEIVED, PR_UNPAID)
         self.save_payment_info(info, write_to_disk=False)
 
-    def register_callback_for_hold_invoice(self, payment_hash: bytes, cb: Callable[[bytes], None]):
+    def register_callback_for_hold_invoice(self, payment_hash: bytes, cb: Callable[[bytes], Awaitable[None]]):
         self.hold_invoice_callbacks[payment_hash] = cb
 
     def save_payment_info(self, info: PaymentInfo, *, write_to_disk: bool = True) -> None:
diff --git a/electrum/plugins/swapserver/server.py b/electrum/plugins/swapserver/server.py
index e8852b8a4..6c5ba1a30 100644
--- a/electrum/plugins/swapserver/server.py
+++ b/electrum/plugins/swapserver/server.py
@@ -1,6 +1,7 @@
 import os
 import asyncio
 from collections import defaultdict
+from typing import TYPE_CHECKING
 
 from aiohttp import web
 
@@ -9,6 +10,11 @@ from electrum.logging import Logger
 from electrum.util import EventListener
 from electrum.lnaddr import lndecode
 
+if TYPE_CHECKING:
+    from electrum.simple_config import SimpleConfig
+    from electrum.wallet import Abstract_Wallet
+
+
 class SwapServer(Logger, EventListener):
     """
     public API:
@@ -18,7 +24,7 @@ class SwapServer(Logger, EventListener):
 
     WWW_DIR = os.path.join(os.path.dirname(__file__), 'www')
 
-    def __init__(self, config, wallet):
+    def __init__(self, config: 'SimpleConfig', wallet: 'Abstract_Wallet'):
         Logger.__init__(self)
         self.config = config
         self.wallet = wallet
diff --git a/electrum/submarine_swaps.py b/electrum/submarine_swaps.py
index 9fa283326..34f2d76c4 100644
--- a/electrum/submarine_swaps.py
+++ b/electrum/submarine_swaps.py
@@ -361,7 +361,7 @@ class SwapManager(Logger):
         callback = lambda: self._claim_swap(swap)
         self.lnwatcher.add_callback(swap.lockup_address, callback)
 
-    async def hold_invoice_callback(self, payment_hash):
+    async def hold_invoice_callback(self, payment_hash: bytes) -> None:
         # note: this assumes the keystore is not encrypted
         key = payment_hash.hex()
         if key in self.swaps: