diff --git a/lib/transaction.py b/lib/transaction.py
index d417030ad145..d93ff2fee558 100644
--- a/lib/transaction.py
+++ b/lib/transaction.py
@@ -936,7 +936,7 @@ def sign(self, keypairs):
                     public_key = private_key.get_verifying_key()
                     sig = private_key.sign_digest_deterministic(pre_hash, hashfunc=hashlib.sha256, sigencode = ecdsa.util.sigencode_der)
                     assert public_key.verify_digest(sig, pre_hash, sigdecode = ecdsa.util.sigdecode_der)
-                    txin['signatures'][j] = bh2u(sig) + '01'
+                    txin['signatures'][j] = bh2u(sig) + '41'
                     #txin['x_pubkeys'][j] = pubkey
                     txin['pubkeys'][j] = pubkey # needed for fd keys
                     self._inputs[i] = txin