diff --git a/Pipfile b/Pipfile
index e4b91f9c6..5f849d993 100644
--- a/Pipfile
+++ b/Pipfile
@@ -23,6 +23,7 @@ pytest-random-order = "*"
 pytest-timeout = "*"
 tox = "*"
 dominate = "*"
+flake8-requirements = ">=1.3.2"
 
 # hardware tests
 pyserial = "*"
diff --git a/pyproject.toml b/pyproject.toml
index 3a82bc80e..67eedaa40 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -73,6 +73,7 @@ inotify = "*"
 
 [tool.poetry.dev-dependencies]
 scan-build = "*"
+flake8-requirements = "^1.3.2"
 
 [build-system]
 requires = ["poetry>=0.12"]
diff --git a/python/requirements.txt b/python/requirements.txt
index e2ad3751d..039f0f9fa 100644
--- a/python/requirements.txt
+++ b/python/requirements.txt
@@ -6,3 +6,4 @@ libusb1>=1.6.4
 construct>=2.9,!=2.10.55
 typing_extensions>=3.7.4
 pyblake2>=0.9.3 ; python_version<'3.6'
+attrs
diff --git a/python/setup.cfg b/python/setup.cfg
index d68a18179..86c820791 100644
--- a/python/setup.cfg
+++ b/python/setup.cfg
@@ -21,6 +21,11 @@ ignore =
     E741,
     # W503: line break before binary operator
     W503
+per-file-ignores =
+    helper-scripts/*:I
+    tools/*:I
+    tests/*:I
+known-modules = libusb1:[usb1],hidapi:[hid],attrs:[attr],PyQt5:[PyQt5.QtWidgets,PyQt5.QtGui,PyQt5.QtCore]
 
 [isort]
 multi_line_output = 3
diff --git a/python/setup.py b/python/setup.py
index cc19e295e..eb9786f9c 100755
--- a/python/setup.py
+++ b/python/setup.py
@@ -14,8 +14,18 @@ install_requires = [
     "construct>=2.9",
     "typing_extensions>=3.7.4",
     "pyblake2>=0.9.3 ; python_version<'3.6'",
+    "attrs",
 ]
 
+extras_require = {
+    "hidapi": ["hidapi>=0.7.99.post20"],
+    "ethereum": ["rlp>=1.1.0", "web3>=4.8"],
+    "qt-widgets": ["PyQt5"],
+    "extra": ["Pillow"],
+}
+
+extras_require["full"] = sum(extras_require.values(), [])
+
 CWD = os.path.dirname(os.path.realpath(__file__))
 
 
@@ -48,10 +58,7 @@ setup(
     package_dir={"": "src"},
     entry_points={"console_scripts": ["trezorctl=trezorlib.cli.trezorctl:cli"]},
     install_requires=install_requires,
-    extras_require={
-        "hidapi": ["hidapi>=0.7.99.post20"],
-        "ethereum": ["rlp>=1.1.0", "web3>=4.8"],
-    },
+    extras_require=extras_require,
     python_requires=">=3.5",
     include_package_data=True,
     zip_safe=False,
diff --git a/python/src/trezorlib/_internal/emulator.py b/python/src/trezorlib/_internal/emulator.py
index 6873cd852..74c7eeb72 100644
--- a/python/src/trezorlib/_internal/emulator.py
+++ b/python/src/trezorlib/_internal/emulator.py
@@ -20,8 +20,8 @@ import subprocess
 import time
 from pathlib import Path
 
-from trezorlib.debuglink import TrezorClientDebugLink
-from trezorlib.transport.udp import UdpTransport
+from ..debuglink import TrezorClientDebugLink
+from ..transport.udp import UdpTransport
 
 LOG = logging.getLogger(__name__)
 
diff --git a/python/src/trezorlib/_internal/firmware_headers.py b/python/src/trezorlib/_internal/firmware_headers.py
index 52758456e..92b15b747 100644
--- a/python/src/trezorlib/_internal/firmware_headers.py
+++ b/python/src/trezorlib/_internal/firmware_headers.py
@@ -5,7 +5,7 @@ from typing import Any, List, Optional
 import click
 import construct as c
 
-from trezorlib import cosi, firmware
+from .. import cosi, firmware
 
 try:
     from hashlib import blake2s
diff --git a/python/src/trezorlib/cli/trezorctl.py b/python/src/trezorlib/cli/trezorctl.py
index 843b52981..9fc613750 100755
--- a/python/src/trezorlib/cli/trezorctl.py
+++ b/python/src/trezorlib/cli/trezorctl.py
@@ -290,7 +290,7 @@ def usb_reset():
     This can fix LIBUSB_ERROR_PIPE and similar errors when connecting to a device
     in a messed state.
     """
-    from trezorlib.transport.webusb import WebUsbTransport
+    from ..transport.webusb import WebUsbTransport
 
     WebUsbTransport.enumerate(usb_reset=True)
 
diff --git a/python/src/trezorlib/qt/pinmatrix.py b/python/src/trezorlib/qt/pinmatrix.py
index dc7d2f66a..c3b52d675 100644
--- a/python/src/trezorlib/qt/pinmatrix.py
+++ b/python/src/trezorlib/qt/pinmatrix.py
@@ -32,7 +32,7 @@ try:
     from PyQt5.QtGui import QRegExpValidator
     from PyQt5.QtCore import QRegExp, Qt, QT_VERSION_STR
 except Exception:
-    from PyQt4.QtGui import (
+    from PyQt4.QtGui import (  # noqa: I
         QPushButton,
         QLineEdit,
         QSizePolicy,
@@ -44,7 +44,7 @@ except Exception:
         QVBoxLayout,
         QHBoxLayout,
     )
-    from PyQt4.QtCore import QObject, SIGNAL, QRegExp, Qt, QT_VERSION_STR
+    from PyQt4.QtCore import QObject, SIGNAL, QRegExp, Qt, QT_VERSION_STR  # noqa: I
 
 
 class PinButton(QPushButton):
diff --git a/setup.cfg b/setup.cfg
index 9749ec730..0c434b7f6 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -13,7 +13,9 @@ ignore =
     # E741 ambiguous variable name
     E741,
     # W503: line break before binary operator
-    W503
+    W503,
+    # flake8-requirements import checks
+    I
 per-file-ignores =
     core/mocks/generated/*:F4