diff --git a/requirements-dev.txt b/requirements-dev.txt
index 2ac5dd064..f89b93afa 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -5,4 +5,4 @@ flake8
 protobuf
 isort
 black; python_version >= "3.6"
-autoflake
+autoflake>=1.2
diff --git a/trezorlib/_ed25519.py b/trezorlib/_ed25519.py
index 53379bfee..f1959ac96 100644
--- a/trezorlib/_ed25519.py
+++ b/trezorlib/_ed25519.py
@@ -32,7 +32,7 @@ arithmetic, so we cannot handle secrets without risking their disclosure.
 """
 
 import hashlib
-from typing import NewType, Tuple
+from typing import List, NewType, Tuple
 
 Point = NewType("Point", Tuple[int, int, int, int])
 
diff --git a/trezorlib/log.py b/trezorlib/log.py
index f8ac86e95..50f778a12 100644
--- a/trezorlib/log.py
+++ b/trezorlib/log.py
@@ -15,7 +15,7 @@
 # If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.
 
 import logging
-from typing import Optional
+from typing import Optional, Set, Type
 
 from . import protobuf
 
diff --git a/trezorlib/transport/__init__.py b/trezorlib/transport/__init__.py
index c81d998b4..e0f54e999 100644
--- a/trezorlib/transport/__init__.py
+++ b/trezorlib/transport/__init__.py
@@ -15,15 +15,11 @@
 # If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.
 
 import logging
-from typing import Iterable, List, Set, Type
+from typing import Iterable, List, Type
 
 from ..exceptions import TrezorException
 from ..protobuf import MessageType
 
-if False:
-    # mark Set and List as used, otherwise they only exist in comments
-    List, Set
-
 LOG = logging.getLogger(__name__)
 
 # USB vendor/product IDs for Trezors
diff --git a/trezorlib/transport/bridge.py b/trezorlib/transport/bridge.py
index 51446d02e..b44949b7c 100644
--- a/trezorlib/transport/bridge.py
+++ b/trezorlib/transport/bridge.py
@@ -24,10 +24,6 @@ import requests
 from . import Transport, TransportException
 from .. import mapping, protobuf
 
-if False:
-    # mark Optional as used, otherwise it only exists in comments
-    Optional
-
 LOG = logging.getLogger(__name__)
 
 TREZORD_HOST = "http://127.0.0.1:21325"
diff --git a/trezorlib/transport/udp.py b/trezorlib/transport/udp.py
index bb0ccfe78..53a8b0ac9 100644
--- a/trezorlib/transport/udp.py
+++ b/trezorlib/transport/udp.py
@@ -20,10 +20,6 @@ from typing import Iterable, Optional, cast
 from . import TransportException
 from .protocol import ProtocolBasedTransport, get_protocol
 
-if False:
-    # mark Optional as used, otherwise it only exists in comments
-    Optional
-
 
 class UdpTransport(ProtocolBasedTransport):
 
diff --git a/trezorlib/transport/webusb.py b/trezorlib/transport/webusb.py
index c1d576412..a4c2840ee 100644
--- a/trezorlib/transport/webusb.py
+++ b/trezorlib/transport/webusb.py
@@ -31,10 +31,6 @@ except Exception as e:
     LOG.warning("WebUSB transport is disabled: {}".format(e))
     usb1 = None
 
-if False:
-    # mark Optional as used, otherwise it only exists in comments
-    Optional
-
 INTERFACE = 0
 ENDPOINT = 1
 DEBUG_INTERFACE = 1