diff --git a/electrum/constants.py b/electrum/constants.py
index 3facd4d66..9e379755d 100644
--- a/electrum/constants.py
+++ b/electrum/constants.py
@@ -25,6 +25,7 @@
 
 import os
 import json
+from typing import Sequence, Tuple, Mapping, Type
 
 from .util import inv_dict, all_subclasses
 from . import bitcoin
@@ -58,6 +59,14 @@ class AbstractNet:
     BLOCK_HEIGHT_FIRST_LIGHTNING_CHANNELS: int = 0
     BIP44_COIN_TYPE: int
     LN_REALM_BYTE: int
+    DEFAULT_PORTS: Mapping[str, str]
+    DEFAULT_SERVERS: Mapping[str, Mapping[str, str]]
+    CHECKPOINTS: Sequence[Tuple[str, int]]
+    LN_DNS_SEEDS: Sequence[str]
+    XPRV_HEADERS: Mapping[str, int]
+    XPRV_HEADERS_INV: Mapping[int, str]
+    XPUB_HEADERS: Mapping[str, int]
+    XPUB_HEADERS_INV: Mapping[int, str]
 
     @classmethod
     def max_checkpoint(cls) -> int:
@@ -184,7 +193,7 @@ class BitcoinSignet(BitcoinTestnet):
 NETS_LIST = tuple(all_subclasses(AbstractNet))
 
 # don't import net directly, import the module instead (so that net is singleton)
-net = BitcoinMainnet
+net = BitcoinMainnet  # type: Type[AbstractNet]
 
 def set_signet():
     global net