diff --git a/src/apps/monero/protocol/tsx_sign_builder.py b/src/apps/monero/protocol/tsx_sign_builder.py
index 3ec651cc1..22ce6b82a 100644
--- a/src/apps/monero/protocol/tsx_sign_builder.py
+++ b/src/apps/monero/protocol/tsx_sign_builder.py
@@ -1163,11 +1163,7 @@ def _set_out1_ecdh(self, idx, dest_pub_key, amount, mask, amount_key):
         return out_pk, ecdh_info_bin
 
     def _set_out1_prefix(self):
-        from apps.monero.xmr.serialize_messages.tx_prefix import TransactionPrefix
-
-        self.tx_prefix_hasher.container_size(
-            self.num_dests(), TransactionPrefix.f_specs()[3][1]
-        )
+        self.tx_prefix_hasher.container_size(self.num_dests())  # ContainerType
 
     def _set_out1_additional_keys(self, dst_entr):
         additional_txkey = None