diff --git a/core/src/apps/wallet/sign_tx/helpers.py b/core/src/apps/wallet/sign_tx/helpers.py
index da5b31438..8ce189521 100644
--- a/core/src/apps/wallet/sign_tx/helpers.py
+++ b/core/src/apps/wallet/sign_tx/helpers.py
@@ -104,14 +104,14 @@ def confirm_nondefault_locktime(lock_time: int):
     return (yield UiConfirmNonDefaultLocktime(lock_time))
 
 
-def request_tx_meta(tx_req: TxRequest, tx_hash: bytes = None):
+def request_tx_meta(tx_req: TxRequest, coin: CoinInfo, tx_hash: bytes = None):
     tx_req.request_type = TXMETA
     tx_req.details.tx_hash = tx_hash
     tx_req.details.request_index = None
     ack = yield tx_req
     tx_req.serialized = None
     gc.collect()
-    return sanitize_tx_meta(ack.tx)
+    return sanitize_tx_meta(ack.tx, coin)
 
 
 def request_tx_extra_data(
@@ -148,7 +148,7 @@ def request_tx_output(tx_req: TxRequest, i: int, coin: CoinInfo, tx_hash: bytes
     tx_req.serialized = None
     gc.collect()
     if tx_hash is None:
-        return sanitize_tx_output(ack.tx)
+        return sanitize_tx_output(ack.tx, coin)
     else:
         return sanitize_tx_binoutput(ack.tx, coin)
 
@@ -165,7 +165,7 @@ def request_tx_finish(tx_req: TxRequest):
 # ===
 
 
-def sanitize_sign_tx(tx: SignTx) -> SignTx:
+def sanitize_sign_tx(tx: SignTx, coin: CoinInfo) -> SignTx:
     tx.version = tx.version if tx.version is not None else 1
     tx.lock_time = tx.lock_time if tx.lock_time is not None else 0
     tx.inputs_count = tx.inputs_count if tx.inputs_count is not None else 0
@@ -177,7 +177,7 @@ def sanitize_sign_tx(tx: SignTx) -> SignTx:
     return tx
 
 
-def sanitize_tx_meta(tx: TransactionType) -> TransactionType:
+def sanitize_tx_meta(tx: TransactionType, coin: CoinInfo) -> TransactionType:
     tx.version = tx.version if tx.version is not None else 1
     tx.lock_time = tx.lock_time if tx.lock_time is not None else 0
     tx.inputs_cnt = tx.inputs_cnt if tx.inputs_cnt is not None else 0
@@ -216,7 +216,7 @@ def sanitize_tx_input(tx: TransactionType, coin: CoinInfo) -> TxInputType:
     return txi
 
 
-def sanitize_tx_output(tx: TransactionType) -> TxOutputType:
+def sanitize_tx_output(tx: TransactionType, coin: CoinInfo) -> TxOutputType:
     txo = tx.outputs[0]
     if txo.multisig and txo.script_type not in MULTISIG_OUTPUT_SCRIPT_TYPES:
         raise SigningError(
diff --git a/core/src/apps/wallet/sign_tx/signing.py b/core/src/apps/wallet/sign_tx/signing.py
index a411cd7a4..71dafe560 100644
--- a/core/src/apps/wallet/sign_tx/signing.py
+++ b/core/src/apps/wallet/sign_tx/signing.py
@@ -55,9 +55,7 @@ class SigningError(ValueError):
 # - check inputs, previous transactions, and outputs
 # - ask for confirmations
 # - check fee
-async def check_tx_fee(tx: SignTx, keychain: seed.Keychain):
-    coin = coins.by_name(tx.coin_name)
-
+async def check_tx_fee(tx: SignTx, keychain: seed.Keychain, coin: coininfo.CoinInfo):
     # h_first is used to make sure the inputs and outputs streamed in Phase 1
     # are the same as in Phase 2.  it is thus not required to fully hash the
     # tx, as the SignTx info is streamed only once
@@ -225,7 +223,9 @@ async def check_tx_fee(tx: SignTx, keychain: seed.Keychain):
 
 
 async def sign_tx(tx: SignTx, keychain: seed.Keychain):
-    tx = helpers.sanitize_sign_tx(tx)
+    coin_name = tx.coin_name if tx.coin_name is not None else "Bitcoin"
+    coin = coins.by_name(coin_name)
+    tx = helpers.sanitize_sign_tx(tx, coin)
 
     progress.init(tx.inputs_count, tx.outputs_count)
 
@@ -238,14 +238,13 @@ async def sign_tx(tx: SignTx, keychain: seed.Keychain):
         authorized_in,
         wallet_path,
         multisig_fp,
-    ) = await check_tx_fee(tx, keychain)
+    ) = await check_tx_fee(tx, keychain, coin)
 
     # Phase 2
     # - sign inputs
     # - check that nothing changed
 
     any_segwit = True in segwit.values()
-    coin = coins.by_name(tx.coin_name)
     tx_ser = TxRequestSerializedType()
 
     txo_bin = TxOutputBinType()
@@ -595,7 +594,7 @@ async def get_prevtx_output_value(
     total_out = 0  # sum of output amounts
 
     # STAGE_REQUEST_2_PREV_META
-    tx = await helpers.request_tx_meta(tx_req, prev_hash)
+    tx = await helpers.request_tx_meta(tx_req, coin, prev_hash)
 
     if tx.outputs_cnt <= prev_index:
         raise SigningError(