diff --git a/core/src/apps/mintlayer/sign_tx/signer.py b/core/src/apps/mintlayer/sign_tx/signer.py
index c95bb4301..6b5e3345f 100644
--- a/core/src/apps/mintlayer/sign_tx/signer.py
+++ b/core/src/apps/mintlayer/sign_tx/signer.py
@@ -158,7 +158,7 @@ def __init__(
         self.chunkify = tx.chunkify or False
         self.tx_req = MintlayerTxRequest()
         self.tx_req.details = MintlayerTxRequestDetailsType()
-        self.tx_req.serialized = []
+        self.tx_req.serialized = None
 
         # The digest of the presigned external inputs streamed for approval in Step 1. This is
         # used to ensure that the inputs streamed for verification in Step 3 are the same as
diff --git a/python/src/trezorlib/cli/__init__.py b/python/src/trezorlib/cli/__init__.py
index 050e3788f..d95385854 100644
--- a/python/src/trezorlib/cli/__init__.py
+++ b/python/src/trezorlib/cli/__init__.py
@@ -158,7 +158,7 @@ def trezorctl_command_with_client(
 
     # the return type of @click.pass_obj is improperly specified and pyright doesn't
     # understand that it converts f(obj, *args, **kwargs) to f(*args, **kwargs)
-    return trezorctl_command_with_client  # type: ignore [is incompatible with return type]
+    return trezorctl_command_with_client
 
 
 class AliasedGroup(click.Group):