diff --git a/electrum/plugins/trustedcoin/trustedcoin.py b/electrum/plugins/trustedcoin/trustedcoin.py
index 92c14cb0b..9bb9491ff 100644
--- a/electrum/plugins/trustedcoin/trustedcoin.py
+++ b/electrum/plugins/trustedcoin/trustedcoin.py
@@ -319,7 +319,7 @@ class Wallet_2fa(Multisig_Wallet):
             return
         otp = int(otp)
         long_user_id, short_id = self.get_user_id()
-        raw_tx = tx.serialize_to_network()
+        raw_tx = tx.serialize()
         r = server.sign(short_id, raw_tx, otp)
         if r:
             raw_tx = r.get('transaction')