diff --git a/apps/note/models/notes.py b/apps/note/models/notes.py
index 938d63d5..0d58195e 100644
--- a/apps/note/models/notes.py
+++ b/apps/note/models/notes.py
@@ -5,7 +5,7 @@ import unicodedata
 
 from django.conf import settings
 from django.conf.global_settings import DEFAULT_FROM_EMAIL
-from django.core.exceptions import ValidationError, PermissionDenied
+from django.core.exceptions import ValidationError
 from django.core.mail import send_mail
 from django.core.validators import RegexValidator
 from django.db import models, transaction
diff --git a/apps/note/models/transactions.py b/apps/note/models/transactions.py
index f887f096..bfe39a42 100644
--- a/apps/note/models/transactions.py
+++ b/apps/note/models/transactions.py
@@ -3,7 +3,6 @@
 
 from django.core.exceptions import ValidationError
 from django.db import models, transaction
-from django.db.models import F
 from django.urls import reverse
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
diff --git a/apps/permission/decorators.py b/apps/permission/decorators.py
index 4dbdbc8e..8ab35697 100644
--- a/apps/permission/decorators.py
+++ b/apps/permission/decorators.py
@@ -4,7 +4,6 @@
 from functools import lru_cache
 from time import time
 
-from django.conf import settings
 from django.contrib.sessions.models import Session
 from note_kfet.middlewares import get_current_session
 
diff --git a/apps/treasury/models.py b/apps/treasury/models.py
index fd8211e6..2606c694 100644
--- a/apps/treasury/models.py
+++ b/apps/treasury/models.py
@@ -307,10 +307,10 @@ class SogeCredit(models.Model):
         if self.valid:
             self.credit_transaction.valid = False
             self.credit_transaction.save()
-        for transaction in self.transactions.all():
-            transaction.valid = False
-            transaction._force_save = True
-            transaction.save()
+        for tr in self.transactions.all():
+            tr.valid = False
+            tr._force_save = True
+            tr.save()
 
     def validate(self, force=False):
         if self.valid and not force:
@@ -325,11 +325,11 @@ class SogeCredit(models.Model):
         self.credit_transaction.save()
         self.save()
 
-        for transaction in self.transactions.all():
-            transaction.valid = True
-            transaction._force_save = True
-            transaction.created_at = timezone.now()
-            transaction.save()
+        for tr in self.transactions.all():
+            tr.valid = True
+            tr._force_save = True
+            tr.created_at = timezone.now()
+            tr.save()
 
     @transaction.atomic
     def save(self, *args, **kwargs):
@@ -364,11 +364,11 @@ class SogeCredit(models.Model):
                                     "Please ask her/him to credit the note before invalidating this credit."))
 
         self.invalidate()
-        for transaction in self.transactions.all():
-            transaction._force_save = True
-            transaction.valid = True
-            transaction.created_at = timezone.now()
-            transaction.save()
+        for tr in self.transactions.all():
+            tr._force_save = True
+            tr.valid = True
+            tr.created_at = timezone.now()
+            tr.save()
         self.credit_transaction.valid = False
         self.credit_transaction.reason += " (invalide)"
         self.credit_transaction.save()