diff --git a/eo_gestion/admin.py b/eo_gestion/admin.py
index 3ff9f41..acdfe60 100644
--- a/eo_gestion/admin.py
+++ b/eo_gestion/admin.py
@@ -17,13 +17,15 @@
 import taggit.admin
 from django.conf import settings
 from django.contrib import admin
-from django.contrib.auth import REDIRECT_FIELD_NAME
+from django.contrib.auth import REDIRECT_FIELD_NAME, get_user_model
 from django.contrib.auth.admin import GroupAdmin, UserAdmin
-from django.contrib.auth.models import Group, User
+from django.contrib.auth.models import Group
 from django.http import HttpResponseRedirect
 from django.utils.http import urlencode
 from django.views.decorators.cache import never_cache
 
+User = get_user_model()
+
 
 class EOGestionAdminSite(admin.AdminSite):
     @never_cache
diff --git a/eo_gestion/eo_facture/forms.py b/eo_gestion/eo_facture/forms.py
index d6867d0..54689ba 100644
--- a/eo_gestion/eo_facture/forms.py
+++ b/eo_gestion/eo_facture/forms.py
@@ -118,14 +118,14 @@ class DuplicateContractForm(forms.Form):
 
 class LigneForm(forms.ModelForm):
     class Meta:
-        exclude = ()
+        fields = '__all__'
         model = models.Ligne
         localized_fields = ("quantite", "prix_unitaire_ht", "taux_tva")
 
 
 class PrestationForm(forms.ModelForm):
     class Meta:
-        exclude = ()
+        fields = '__all__'
         model = models.Prestation
         localized_fields = ("quantite", "prix_unitaire_ht")
 
@@ -181,14 +181,14 @@ class FactureForm(forms.ModelForm):
             )
 
     class Meta:
-        exclude = ()
+        fields = '__all__'
         model = models.Facture
         localized_fields = ("taux_tva",)
 
 
 class ClientForm(forms.ModelForm):
     class Meta:
-        exclude = ()
+        fields = '__all__'
         model = models.Client
         localized_fields = ("tva",)
         widgets = {
@@ -199,13 +199,13 @@ class ClientForm(forms.ModelForm):
 
 class ContratForm(forms.ModelForm):
     class Meta:
-        exclude = ()
+        fields = '__all__'
         model = models.Contrat
         localized_fields = ("tva", "montant_sous_traite")
 
 
 class PaymentForm(forms.ModelForm):
     class Meta:
-        exclude = ()
+        fields = '__all__'
         model = models.Payment
         localized_fields = ("montant_affecte",)
diff --git a/eo_gestion/eo_facture/models.py b/eo_gestion/eo_facture/models.py
index f5b0614..3a18727 100644
--- a/eo_gestion/eo_facture/models.py
+++ b/eo_gestion/eo_facture/models.py
@@ -20,7 +20,7 @@ from collections import defaultdict
 from decimal import ROUND_HALF_UP, Decimal
 
 from django.conf import settings
-from django.contrib.auth.models import User
+from django.contrib.auth import get_user_model
 from django.core.exceptions import ValidationError
 from django.core.validators import RegexValidator, validate_email
 from django.db import models
@@ -37,6 +37,8 @@ from eo_gestion.utils import percentage_str
 from ..eo_banque import models as banque_models
 from . import facturx, fields, taggit, validators
 
+User = get_user_model()
+
 validate_telephone = RegexValidator(r"[. 0-9]*")
 
 DEFAULT_TVA = getattr(settings, "TVA", "20")
diff --git a/eo_gestion/eo_facture/views.py b/eo_gestion/eo_facture/views.py
index bf2f0b0..8568aaa 100644
--- a/eo_gestion/eo_facture/views.py
+++ b/eo_gestion/eo_facture/views.py
@@ -15,7 +15,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-import json
 import logging
 import os.path
 
@@ -78,7 +77,7 @@ def api_references(request):
         )
         if contract.image:
             data[-1]['image'] = request.build_absolute_uri(contract.image.url)
-    return http.HttpResponse(json.dumps({'data': data}), content_type='application/json')
+    return http.JsonResponse({'data': data})
 
 
 def send_to_chorus(request, facture_id):
diff --git a/tests/conftest.py b/tests/conftest.py
index c8e34bc..60c5b61 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -16,9 +16,11 @@
 
 import django_webtest
 import pytest
-from django.contrib.auth.models import User
+from django.contrib.auth import get_user_model
 from django.core.management import call_command
 
+User = get_user_model()
+
 DATA = ["tests/fixture.json"]
 
 
diff --git a/tests/test_forms.py b/tests/test_forms.py
index eef0ca7..e4e9efd 100644
--- a/tests/test_forms.py
+++ b/tests/test_forms.py
@@ -16,11 +16,13 @@
 
 from datetime import date, timedelta
 
-from django.contrib.auth.models import User
+from django.contrib.auth import get_user_model
 
 from eo_gestion.eo_facture.forms import FactureForm
 from eo_gestion.eo_facture.models import Client, Contrat
 
+User = get_user_model()
+
 
 def test_facture_form(db, freezer):
     freezer.move_to('2019-01-01')