diff --git a/.isort.cfg b/.isort.cfg
index 249c22f..09e6830 100644
--- a/.isort.cfg
+++ b/.isort.cfg
@@ -9,4 +9,4 @@ line_length=88
 known_odoo=odoo
 known_odoo_addons=odoo.addons
 sections=FUTURE,STDLIB,THIRDPARTY,ODOO,ODOO_ADDONS,FIRSTPARTY,LOCALFOLDER
-known_third_party=openerp,requests,simplejson
+known_third_party=openerp,requests
diff --git a/mailgun/models.py b/mailgun/models.py
index d1bdbd5..7b3430c 100644
--- a/mailgun/models.py
+++ b/mailgun/models.py
@@ -2,9 +2,13 @@
 import logging
 
 import requests
-import simplejson
 from openerp import api, models
 
+try:
+    import simplejson as json
+except ImportError:
+    import json
+
 _logger = logging.getLogger(__name__)
 
 
@@ -38,6 +42,6 @@ class IrConfigParameter(models.Model):
             res = requests.put(url, auth=("api", api_key))
             if (
                 res.status_code == 200
-                and simplejson.loads(res.text)["domain"]["state"] == "active"
+                and json.loads(res.text)["domain"]["state"] == "active"
             ):
                 self.set_param("mailgun.verified", "1")