diff --git a/passerelle_imio_extra_fees/models.py b/passerelle_imio_extra_fees/models.py
index a460c0b..80d3dbc 100644
--- a/passerelle_imio_extra_fees/models.py
+++ b/passerelle_imio_extra_fees/models.py
@@ -16,7 +16,7 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-import json
+
 
 from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models
@@ -24,6 +24,7 @@ from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 
 from passerelle.base.models import BaseResource
+from passerelle.compat import json_loads
 from passerelle.utils.api import endpoint
 from decimal import Decimal
 
@@ -57,7 +58,7 @@ class ExtraFees(BaseResource):
     def default_compute(self, request, **kwargs):
         nb_documents = 0
         nb_letter = 0
-        data = json.loads(request.body.decode('utf-8'))
+        data = json_loads(request.body.decode('utf-8'))
         postage_fee = Decimal(self.belgium_postage_fee)
         for basket_item in data['data']:
             try:
@@ -72,7 +73,7 @@ class ExtraFees(BaseResource):
         return {'data': [{'subject': force_text(_('Postage')), 'amount': str(postage_fee)}]}
 
     def namur_compute(self, request, **kwargs):
-        data = json.loads(request.body)
+        data = json_loads(request.body)
         # EXCEPTIONS :
         # duplicata-de-livret-de-mariage (frais port 8 ou 13)
         # demande-de-changement-d-adresse-domicile (frais port 0)