diff --git a/apps/participation/models.py b/apps/participation/models.py
index b62b1a9..41aa5c2 100644
--- a/apps/participation/models.py
+++ b/apps/participation/models.py
@@ -1,22 +1,19 @@
-import asyncio
 import os
 import re
 
-from django.template.loader import render_to_string
-from nio import RoomVisibility, RoomPreset
-
 from corres2math.lists import get_sympa_client
+from corres2math.matrix import Matrix
 from django.core.exceptions import ObjectDoesNotExist
 from django.core.validators import RegexValidator
 from django.db import models
 from django.db.models import Index
+from django.template.loader import render_to_string
 from django.urls import reverse_lazy
 from django.utils import timezone
 from django.utils.crypto import get_random_string
 from django.utils.text import format_lazy
 from django.utils.translation import gettext_lazy as _
-
-from corres2math.matrix import Matrix
+from nio import RoomPreset, RoomVisibility
 
 
 class Team(models.Model):
diff --git a/apps/participation/views.py b/apps/participation/views.py
index b9345b9..8767091 100644
--- a/apps/participation/views.py
+++ b/apps/participation/views.py
@@ -1,10 +1,6 @@
-import asyncio
 from io import BytesIO
 from zipfile import ZipFile
 
-from django.shortcuts import redirect
-from django.views.generic.base import TemplateView
-
 from corres2math.lists import get_sympa_client
 from corres2math.matrix import Matrix
 from corres2math.views import AdminMixin
@@ -13,10 +9,12 @@ from django.core.exceptions import PermissionDenied
 from django.core.mail import send_mail
 from django.db import transaction
 from django.http import HttpResponse
+from django.shortcuts import redirect
 from django.template.loader import render_to_string
 from django.urls import reverse_lazy
 from django.utils.translation import gettext_lazy as _
 from django.views.generic import CreateView, DetailView, FormView, RedirectView, UpdateView
+from django.views.generic.base import TemplateView
 from django.views.generic.edit import FormMixin, ProcessFormView
 from django_tables2 import SingleTableView
 from magic import Magic
diff --git a/corres2math/matrix.py b/corres2math/matrix.py
index ea6274d..35ba498 100644
--- a/corres2math/matrix.py
+++ b/corres2math/matrix.py
@@ -1,9 +1,8 @@
-import asyncio
 from typing import Any, Dict, Optional, Union
 
 from asgiref.sync import async_to_sync
-from nio import AsyncClient, RoomCreateError, RoomCreateResponse, RoomInviteError, RoomInviteResponse, RoomPreset, \
-    RoomVisibility, RoomResolveAliasResponse
+from nio import AsyncClient, RoomCreateError, RoomCreateResponse, RoomKickResponse, RoomInviteError,\
+    RoomInviteResponse, RoomPreset, RoomResolveAliasResponse, RoomVisibility
 
 
 class Matrix: