diff --git a/aleksis/core/apps.py b/aleksis/core/apps.py
index ba0e5cbd893fbd74a12644045349a084ca2f1008..dd3c9b3a8cafb9a6a0ae77fa7253f9a58ab76395 100644
--- a/aleksis/core/apps.py
+++ b/aleksis/core/apps.py
@@ -1,7 +1,6 @@
 from typing import Any, List, Optional, Tuple
 
 import django.apps
-from django.contrib.auth import get_user_model
 from django.http import HttpRequest
 
 from dynamic_preferences.registries import preference_models
@@ -15,8 +14,6 @@ from .util.apps import AppConfig
 from .util.core_helpers import has_person
 from .util.sass_helpers import clean_scss
 
-User = get_user_model()
-
 
 class CoreConfig(AppConfig):
     name = "aleksis.core"
@@ -39,13 +36,13 @@ class CoreConfig(AppConfig):
     def ready(self):
         super().ready()
 
-        SitePreferenceModel = self.get_model("SitePreferenceModel")
-        PersonPreferenceModel = self.get_model("PersonPreferenceModel")
-        GroupPreferenceModel = self.get_model("GroupPreferenceModel")
+        sitepreferencemodel = self.get_model("SitePreferenceModel")
+        personpreferencemodel = self.get_model("PersonPreferenceModel")
+        grouppreferencemodel = self.get_model("GroupPreferenceModel")
 
-        preference_models.register(SitePreferenceModel, site_preferences_registry)
-        preference_models.register(PersonPreferenceModel, person_preferences_registry)
-        preference_models.register(GroupPreferenceModel, group_preferences_registry)
+        preference_models.register(sitepreferencemodel, site_preferences_registry)
+        preference_models.register(personpreferencemodel, person_preferences_registry)
+        preference_models.register(grouppreferencemodel, group_preferences_registry)
 
     def preference_updated(
         self,
diff --git a/aleksis/core/forms.py b/aleksis/core/forms.py
index 2fcafc68ba35e6e9d650bc9d2d6e9b73e223fdb2..888926e5871ea70d4cebd9d8b7b0eb33fb4aa8cd 100644
--- a/aleksis/core/forms.py
+++ b/aleksis/core/forms.py
@@ -36,7 +36,7 @@ class PersonAccountForm(forms.ModelForm):
         self.fields["last_name"].disabled = True
 
     def clean(self) -> None:
-        User = get_user_model()
+        user = get_user_model()
 
         if self.cleaned_data.get("new_user", None):
             if self.cleaned_data.get("user", None):
@@ -45,12 +45,12 @@ class PersonAccountForm(forms.ModelForm):
                     "new_user",
                     _("You cannot set a new username when also selecting an existing user."),
                 )
-            elif User.objects.filter(username=self.cleaned_data["new_user"]).exists():
+            elif user.objects.filter(username=self.cleaned_data["new_user"]).exists():
                 # The user tried to create a new user with the name of an existing user
                 self.add_error("new_user", _("This username is already in use."))
             else:
                 # Create new User object and assign to form field for existing user
-                new_user_obj = User.objects.create_user(
+                new_user_obj = user.objects.create_user(
                     self.cleaned_data["new_user"],
                     self.instance.email,
                     first_name=self.instance.first_name,
diff --git a/aleksis/core/mixins.py b/aleksis/core/mixins.py
index 7d1bd2c294d0f4adbcdf6218088809cf404b9f54..f65941f8592fa08946bc457364313cc5e4cb8ebb 100644
--- a/aleksis/core/mixins.py
+++ b/aleksis/core/mixins.py
@@ -187,7 +187,7 @@ class PureDjangoModel(object):
 
 
 class _ExtensibleFormMetaclass(ModelFormMetaclass):
-    def __new__(mcs, name, bases, dct):
+    def __new__(cls, mcs, name, bases, dct):
         x = super().__new__(mcs, name, bases, dct)
 
         # Enforce a default for the base layout for forms that o not specify one
diff --git a/aleksis/core/models.py b/aleksis/core/models.py
index 0af29fe21504b263e0661b6eef1db78894e12e23..b2bcf3968b51fd01a91d54996af6eee0aab36477 100644
--- a/aleksis/core/models.py
+++ b/aleksis/core/models.py
@@ -185,8 +185,8 @@ class Person(ExtensibleModel):
     @classmethod
     def maintain_default_data(cls):
         # Ensure we have an admin user
-        User = get_user_model()
-        if not User.objects.filter(is_superuser=True).exists():
+        user = get_user_model()
+        if not user.objects.filter(is_superuser=True).exists():
             admin = User.objects.create_superuser(
                 username="admin", email="root@example.com", password="admin"
             )
diff --git a/aleksis/core/settings.py b/aleksis/core/settings.py
index f7e2dcd4c077a3795e61a3f8e8c798ba1e1c4baa..e6da76d828a0a8c8bd3320ac748c98e87bf5c973 100644
--- a/aleksis/core/settings.py
+++ b/aleksis/core/settings.py
@@ -4,7 +4,7 @@ from glob import glob
 from django.utils.translation import gettext_lazy as _
 
 from dynaconf import LazySettings
-from easy_thumbnails.conf import Settings as thumbnail_settings
+from easy_thumbnails.conf import settings as thumbnail_settings
 
 from .util.core_helpers import (
     get_app_packages,
diff --git a/aleksis/core/util/notifications.py b/aleksis/core/util/notifications.py
index 3dfb11aa86ca0553081075fb064c8dd1e75ed922..499de67b9fba6513e680d6bd6354505b83396b49 100644
--- a/aleksis/core/util/notifications.py
+++ b/aleksis/core/util/notifications.py
@@ -77,10 +77,10 @@ def send_notification(notification: Union[int, "Notification"], resend: bool = F
     channels = lazy_preference("notification", "channels")
 
     if isinstance(notification, int):
-        Notification = apps.get_model("core", "Notification")
-        notification = Notification.objects.get(pk=notification)
+        notification = apps.get_model("core", "Notification")
+        notification_ = notification.objects.get(pk=notification)
 
-    if resend or not notification.sent:
+    if resend or not notification_.sent:
         for channel in channels:
             name, check, send = _CHANNELS_MAP[channel]
             if check():
diff --git a/tox.ini b/tox.ini
index 36687847e9b2dd82018c8363190e80ca20304e28..4f3427737969fabf2293bcf97f3fa917483c5c5f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -48,7 +48,7 @@ commands =
 [flake8]
 max_line_length = 100
 exclude = migrations,tests
-ignore = BLK100,E203,E231,W503,D100,D101,D102,D103,D104,D105,D106,D107,RST215,RST214,F841,S106
+ignore = BLK100,E203,E231,W503,D100,D101,D102,D103,D104,D105,D106,D107,RST215,RST214,F821,F841,S106,T100,T101
 
 [isort]
 line_length = 100