diff --git a/tests/test_mnemonic.py b/tests/test_mnemonic.py
index ebbb9cbc4..45a10df26 100644
--- a/tests/test_mnemonic.py
+++ b/tests/test_mnemonic.py
@@ -188,6 +188,11 @@ class Test_seeds(ElectrumTestCase):
         ('science dawn member doll dutch real can brick knife deny drive list', '2fa'),
         ('science dawn member doll dutch real ca brick knife deny drive list', ''),
         (' sCience dawn   member doll Dutch rEAl can brick knife deny drive  lisT', '2fa'),
+        # pre-version-2.7 2fa seed with 25 words:
+        ('bind clever room kidney crucial sausage spy edit canvas soul liquid ribbon slam open alpha suffer gate relax voice carpet law hill woman tonight abstract', '2fa'),
+        ('  bInd cLEveR    room kidney crucial sausage spy edit canvas soul liquid ribbon SLAM open alpha suffer gate relax voice carpet law hill woman tonight abstract ', '2fa'),
+        # pre-version-2.7 2fa seed with 24 words:
+        ('sibling leg cable timber patient foot occur plate travel finger chef scale radio citizen promote immune must chef fluid sea sphere common acid lab', '2fa'),
         ('frost pig brisk excite novel report camera enlist axis nation novel desert', 'segwit'),
         ('  fRoSt pig brisk excIte novel rePort CamEra enlist axis nation nOVeL dEsert ', 'segwit'),
         # short seed cheat sheet:
diff --git a/tests/test_wallet_vertical.py b/tests/test_wallet_vertical.py
index e0578d5f9..a75b85407 100644
--- a/tests/test_wallet_vertical.py
+++ b/tests/test_wallet_vertical.py
@@ -33,6 +33,7 @@ assert UNICODE_HORROR == '₿ 😀 😈     う けたま わる w͢͢͝h͡o͢͡
 class WalletIntegrityHelper:
 
     gap_limit = 1  # make tests run faster
+    # TODO also use short gap limit for change addrs, for performance
 
     @classmethod
     def check_seeded_keystore_sanity(cls, test_obj, ks):
@@ -169,9 +170,10 @@ class TestWalletKeystoreAddressIntegrityForMainnet(ElectrumTestCase):
         self.assertEqual(w.get_change_addresses()[0], '1KRW8pH6HFHZh889VDq6fEKvmrsmApwNfe')
 
     @mock.patch.object(wallet.Abstract_Wallet, 'save_db')
-    async def test_electrum_seed_2fa_legacy_pre27(self, mock_save_db):
-        # pre-version-2.7 2fa seed
+    async def test_electrum_seed_2fa_legacy_pre27_25words(self, mock_save_db):
+        # pre-version-2.7 2fa seed, containing 25 words
         seed_words = 'bind clever room kidney crucial sausage spy edit canvas soul liquid ribbon slam open alpha suffer gate relax voice carpet law hill woman tonight abstract'
+        assert len(seed_words.split()) == 25
         self.assertEqual(seed_type(seed_words), '2fa')
 
         xprv1, xpub1, xprv2, xpub2 = trustedcoin.TrustedCoinPlugin.xkeys_from_seed(seed_words, '')
@@ -203,6 +205,42 @@ class TestWalletKeystoreAddressIntegrityForMainnet(ElectrumTestCase):
         self.assertEqual(w.get_receiving_addresses()[0], '3Bw5jczNModhFAbvfwvUHbdGrC2Lh2qRQp')
         self.assertEqual(w.get_change_addresses()[0], '3Ke6pKrmtSyyQaMob1ES4pk8siAAkRmst9')
 
+    @mock.patch.object(wallet.Abstract_Wallet, 'save_db')
+    async def test_electrum_seed_2fa_legacy_pre27_24words(self, mock_save_db):
+        # pre-version-2.7 2fa seed, containing 24 words
+        seed_words = 'sibling leg cable timber patient foot occur plate travel finger chef scale radio citizen promote immune must chef fluid sea sphere common acid lab'
+        assert len(seed_words.split()) == 24
+        self.assertEqual(seed_type(seed_words), '2fa')
+
+        xprv1, xpub1, xprv2, xpub2 = trustedcoin.TrustedCoinPlugin.xkeys_from_seed(seed_words, '')
+
+        ks1 = keystore.from_xprv(xprv1)
+        self.assertTrue(isinstance(ks1, keystore.BIP32_KeyStore))
+        self.assertEqual(ks1.xprv, 'xprv9s21ZrQH143K37iqjPnsBm27cRgrg6TiKNwhCYg7Uk46yLKB5s4N1Knzo7rTkYvjojh9Z6KkGTMi6CV5h4kEcWYLmHjcTW8kK5bnMVXvEvp')
+        self.assertEqual(ks1.xpub, 'xpub661MyMwAqRbcFboJqRKsYtxrATXM5ZBZgbsHzw5j35b5r8eKdQNcZ87UeR24LDSn2RxspwL9s7yM3KqtPFq5dwP5csmQ2Xb1dgaQztrNGyP')
+        self.assertEqual(ks1.xpub, xpub1)
+
+        ks2 = keystore.from_xprv(xprv2)
+        self.assertTrue(isinstance(ks2, keystore.BIP32_KeyStore))
+        self.assertEqual(ks2.xprv, 'xprv9s21ZrQH143K2qJ6sVTs5bXnrw7CPEpYTkefvW6Xj9fMuskny5t3TaLMAvZtSkYwT68asJdrEaay8q4ntmXvYCuQL3ULdEziFCB9KyZhuDX')
+        self.assertEqual(ks2.xpub, 'xpub661MyMwAqRbcFKNZyWzsSjUXQxwgnhYPpyaGitW9HVCLng5wWdCJ1Neq2DLV3717ED1RG3aTGLJVVBt5CJEXmCzMLBjqXtK4MEvRXiYSvnJ')
+        self.assertEqual(ks2.xpub, xpub2)
+
+        long_user_id, short_id = trustedcoin.get_user_id(
+            {'x1': {'xpub': xpub1},
+             'x2': {'xpub': xpub2}})
+        xtype = bip32.xpub_type(xpub1)
+        xpub3 = trustedcoin.make_xpub(trustedcoin.get_signing_xpub(xtype), long_user_id)
+        ks3 = keystore.from_xpub(xpub3)
+        WalletIntegrityHelper.check_xpub_keystore_sanity(self, ks3)
+        self.assertTrue(isinstance(ks3, keystore.BIP32_KeyStore))
+
+        w = WalletIntegrityHelper.create_multisig_wallet([ks1, ks2, ks3], '2of3', config=self.config)
+        self.assertEqual(w.txin_type, 'p2sh')
+
+        self.assertEqual(w.get_receiving_addresses()[0], '39XK9VBGiK4bqNJYrajfKE8C1ky4gYA5Zy')
+        self.assertEqual(w.get_change_addresses()[0], '3PKtHrjiKdsZ73ULZ4Sf1vDBnrUoAEtLDe')
+
     @mock.patch.object(wallet.Abstract_Wallet, 'save_db')
     async def test_electrum_seed_2fa_legacy_post27(self, mock_save_db):
         # post-version-2.7 2fa seed