diff --git a/aleksis/core/apps.py b/aleksis/core/apps.py
index 4f243858d97bb458b59c03ddb99ba67fd771a0c2..0037842bc71590eb521aa67f25b5f4cc6b50fb92 100644
--- a/aleksis/core/apps.py
+++ b/aleksis/core/apps.py
@@ -2,7 +2,6 @@ from typing import Any, List, Optional, Tuple
 
 import django.apps
 from django.http import HttpRequest
-from django.core.files.uploadedfile import TemporaryUploadedFile
 
 from dynamic_preferences.registries import preference_models
 
@@ -65,7 +64,7 @@ class CoreConfig(AppConfig):
                 if new_value:
                     Favicon.on_site.update_or_create(
                         title=name,
-                        defaults={"isFavicon": name == "favicon", "faviconImage": new_value, },
+                        defaults={"isFavicon": name == "favicon", "faviconImage": new_value,},
                     )
                 else:
                     Favicon.on_site.filter(title=name, isFavicon=is_favicon).delete()
diff --git a/aleksis/core/mixins.py b/aleksis/core/mixins.py
index ca5ffc85552ebe4267b4c7cf0a6d93bb0df7b7ef..b6ae0b04cda77bca46ddfe7af53943086c8d5b38 100644
--- a/aleksis/core/mixins.py
+++ b/aleksis/core/mixins.py
@@ -1,3 +1,5 @@
+# flake8: noqa: DJ12
+
 from datetime import datetime
 from typing import Any, Callable, List, Optional, Tuple, Union
 
diff --git a/aleksis/core/models.py b/aleksis/core/models.py
index 6f4fff67654ff11857a56c25c6cb89fbedf0833c..b5bb204c25139c463e6d53c27b7c1ddf51b75576 100644
--- a/aleksis/core/models.py
+++ b/aleksis/core/models.py
@@ -1,3 +1,5 @@
+# flake8: noqa: DJ01
+
 from datetime import date, datetime
 from typing import Iterable, List, Optional, Sequence, Union
 
@@ -81,7 +83,7 @@ class Person(ExtensibleModel):
     )
 
     short_name = models.CharField(
-        verbose_name=_("Short name"), max_length=255, blank=True, null=True, unique=True # noqa
+        verbose_name=_("Short name"), max_length=255, blank=True, null=True, unique=True  # noqa
     )
 
     street = models.CharField(verbose_name=_("Street"), max_length=255, blank=True)
@@ -151,16 +153,15 @@ class Person(ExtensibleModel):
     @property
     def mail_sender(self) -> str:
         """E-mail sender in "Name <email>" format."""
-        return f"\"{self.addressing_name}\" <{self.email}>"
+        return f'"{self.addressing_name}" <{self.email}>'
 
     @property
     def mail_sender_via(self) -> str:
         """E-mail sender for via addresses, in "Name via Site <email>" format."""
-
         site_mail = get_site_preferences()["mail__address"]
         site_name = get_site_preferences()["general__title"]
 
-        return f"\"{self.addressing_name} via {site_name}\" <{site_mail}>"
+        return f'"{self.addressing_name} via {site_name}" <{site_mail}>'
 
     @property
     def age(self):
@@ -271,7 +272,7 @@ class Group(ExtensibleModel):
 
     name = models.CharField(verbose_name=_("Long name"), max_length=255, unique=True)
     short_name = models.CharField(
-        verbose_name=_("Short name"), max_length=255, unique=True, blank=True, null=True # noqa
+        verbose_name=_("Short name"), max_length=255, unique=True, blank=True, null=True  # noqa
     )
 
     members = models.ManyToManyField(
diff --git a/aleksis/core/templatetags/html_helpers.py b/aleksis/core/templatetags/html_helpers.py
index 77b198f3f2cf7eff0a48ec39fb2924db8c047840..a30a230ce4f9aebdf93499ef8ff511befe2a8871 100644
--- a/aleksis/core/templatetags/html_helpers.py
+++ b/aleksis/core/templatetags/html_helpers.py
@@ -11,7 +11,6 @@ def add_class_to_el(value: str, arg: str) -> str:
 
     Example: {{ mymodel.myhtmlfield|add_class_to_el:"ul,browser-default"
     """
-
     el, cls = arg.split(",")
     soup = BeautifulSoup(value, "html.parser")
 
diff --git a/aleksis/core/util/core_helpers.py b/aleksis/core/util/core_helpers.py
index 67c9daae584fbdbe84294b8439d7cfb20481aa01..522b930d4c73286051b829cb001d33fa49908fcd 100644
--- a/aleksis/core/util/core_helpers.py
+++ b/aleksis/core/util/core_helpers.py
@@ -228,6 +228,6 @@ def objectgetter_optional(
         if id_ is not None:
             return get_object_or_404(model, pk=id_)
         else:
-            return eval(default) if default_eval else default
+            return eval(default) if default_eval else default  # noqa:S307
 
     return get_object