diff --git a/python/src/trezorlib/_ed25519.py b/python/src/trezorlib/_ed25519.py
index f1959ac96a..74c1e2f5f2 100644
--- a/python/src/trezorlib/_ed25519.py
+++ b/python/src/trezorlib/_ed25519.py
@@ -154,7 +154,7 @@ def scalarmult(P: Point, e: int) -> Point:
 
 
 # Bpow[i] == scalarmult(B, 2**i)
-Bpow = []  # type: List[Point]
+Bpow: List[Point] = []
 
 
 def make_Bpow() -> None:
diff --git a/python/src/trezorlib/log.py b/python/src/trezorlib/log.py
index 5740ecc533..696a150c34 100644
--- a/python/src/trezorlib/log.py
+++ b/python/src/trezorlib/log.py
@@ -19,7 +19,7 @@ from typing import Optional, Set, Type
 
 from . import protobuf
 
-OMITTED_MESSAGES = set()  # type: Set[Type[protobuf.MessageType]]
+OMITTED_MESSAGES: Set[Type[protobuf.MessageType]] = set()
 
 DUMP_BYTES = 5
 DUMP_PACKETS = 4
diff --git a/python/src/trezorlib/protobuf.py b/python/src/trezorlib/protobuf.py
index 836d991f61..0df86fe80f 100644
--- a/python/src/trezorlib/protobuf.py
+++ b/python/src/trezorlib/protobuf.py
@@ -584,7 +584,7 @@ def dict_to_proto(message_type: Type[MT], d: Dict[str, Any]) -> MT:
             value = [value]
 
         if isinstance(ftype, type) and issubclass(ftype, MessageType):
-            function = dict_to_proto  # type: Callable[[Any, Any], Any]
+            function: Callable[[Any, Any], Any] = dict_to_proto
         else:
             function = value_to_proto
 
diff --git a/python/src/trezorlib/toif.py b/python/src/trezorlib/toif.py
index 82b990ab03..fd464bed5a 100644
--- a/python/src/trezorlib/toif.py
+++ b/python/src/trezorlib/toif.py
@@ -63,9 +63,9 @@ def _to_grayscale(data: bytes) -> bytes:
 
 @attr.s
 class Toif:
-    mode = attr.ib()  # type: firmware.ToifMode
-    size = attr.ib()  # type: Tuple[int, int]
-    data = attr.ib()  # type: bytes
+    mode: firmware.ToifMode = attr.ib()
+    size: Tuple[int, int] = attr.ib()
+    data: bytes = attr.ib()
 
     @data.validator
     def check_data_size(self, _, value):
diff --git a/python/src/trezorlib/transport/__init__.py b/python/src/trezorlib/transport/__init__.py
index f71642cc39..6e1e6f178a 100644
--- a/python/src/trezorlib/transport/__init__.py
+++ b/python/src/trezorlib/transport/__init__.py
@@ -58,7 +58,7 @@ class Transport:
     a Trezor device to a computer.
     """
 
-    PATH_PREFIX = None  # type: str
+    PATH_PREFIX: str = None
     ENABLED = False
 
     def __str__(self) -> str:
@@ -112,7 +112,7 @@ def all_transports() -> Iterable[Type[Transport]]:
 
 
 def enumerate_devices() -> Iterable[Transport]:
-    devices = []  # type: List[Transport]
+    devices: List[Transport] = []
     for transport in all_transports():
         name = transport.__name__
         try:
diff --git a/python/src/trezorlib/transport/bridge.py b/python/src/trezorlib/transport/bridge.py
index 54e8e53928..df3136f3a9 100644
--- a/python/src/trezorlib/transport/bridge.py
+++ b/python/src/trezorlib/transport/bridge.py
@@ -76,7 +76,7 @@ class BridgeHandleModern(BridgeHandle):
 class BridgeHandleLegacy(BridgeHandle):
     def __init__(self, transport: "BridgeTransport") -> None:
         super().__init__(transport)
-        self.request = None  # type: Optional[str]
+        self.request: Optional[str] = None
 
     def write_buf(self, buf: bytes) -> None:
         if self.request is not None:
@@ -110,12 +110,12 @@ class BridgeTransport(Transport):
             raise TransportException("Debugging not supported on legacy Bridge")
 
         self.device = device
-        self.session = None  # type: Optional[str]
+        self.session: Optional[str] = None
         self.debug = debug
         self.legacy = legacy
 
         if legacy:
-            self.handle = BridgeHandleLegacy(self)  # type: BridgeHandle
+            self.handle: BridgeHandle = BridgeHandleLegacy(self)
         else:
             self.handle = BridgeHandleModern(self)
 
diff --git a/python/src/trezorlib/transport/hid.py b/python/src/trezorlib/transport/hid.py
index 97865f3e51..4dd120a50e 100644
--- a/python/src/trezorlib/transport/hid.py
+++ b/python/src/trezorlib/transport/hid.py
@@ -42,7 +42,7 @@ class HidHandle:
     ) -> None:
         self.path = path
         self.serial = serial
-        self.handle = None  # type: HidDeviceHandle
+        self.handle: HidDeviceHandle = None
         self.hid_version = None if probe_hid_version else 2
 
     def open(self) -> None:
diff --git a/python/src/trezorlib/transport/udp.py b/python/src/trezorlib/transport/udp.py
index e95830f972..447ae24986 100644
--- a/python/src/trezorlib/transport/udp.py
+++ b/python/src/trezorlib/transport/udp.py
@@ -44,7 +44,7 @@ class UdpTransport(ProtocolBasedTransport):
             host = devparts[0]
             port = int(devparts[1]) if len(devparts) > 1 else UdpTransport.DEFAULT_PORT
         self.device = (host, port)
-        self.socket = None  # type: Optional[socket.socket]
+        self.socket: Optional[socket.socket] = None
 
         super().__init__(protocol=ProtocolV1(self))
 
diff --git a/python/src/trezorlib/transport/webusb.py b/python/src/trezorlib/transport/webusb.py
index 40cd1ea408..ba6db9dc35 100644
--- a/python/src/trezorlib/transport/webusb.py
+++ b/python/src/trezorlib/transport/webusb.py
@@ -44,7 +44,7 @@ class WebUsbHandle:
         self.interface = DEBUG_INTERFACE if debug else INTERFACE
         self.endpoint = DEBUG_ENDPOINT if debug else ENDPOINT
         self.count = 0
-        self.handle = None  # type: Optional[usb1.USBDeviceHandle]
+        self.handle: Optional[usb1.USBDeviceHandle] = None
 
     def open(self) -> None:
         self.handle = self.device.open()