diff --git a/tests/test_device_mqtt.py b/tests/test_device_mqtt.py
index 2f8149e9..377137d5 100644
--- a/tests/test_device_mqtt.py
+++ b/tests/test_device_mqtt.py
@@ -509,7 +509,9 @@ def test_send(self, mock_get_interface, mock_bson_dumps, mock_db_store, mock_mqt
     @mock.patch.object(AstarteDatabaseSQLite, "store_prop")
     @mock.patch("astarte.device.device_mqtt.bson.dumps")
     @mock.patch.object(Introspection, "get_interface")
-    def test_send_zero_is_ok(self, mock_get_interface, mock_bson_dumps, mock_db_store, mock_mqtt_publish):
+    def test_send_zero_is_ok(
+        self, mock_get_interface, mock_bson_dumps, mock_db_store, mock_mqtt_publish
+    ):
         device = self.helper_initialize_device(loop=None)
 
         mock_interface = mock.MagicMock()