diff --git a/gns3server/controller/link.py b/gns3server/controller/link.py
index e784dd1b..502c2959 100644
--- a/gns3server/controller/link.py
+++ b/gns3server/controller/link.py
@@ -368,7 +368,7 @@ class Link:
             if node["node"].node_type in ('vpcs',
                                           'dynamips',
                                           'qemu',
-                                          'iou'):
+                                          'iou',
                                           'cloud',
                                           'nat',
                                           'docker'):
@@ -383,11 +383,11 @@ class Link:
     def __hash__(self):
         return hash(self._id)
 
-    def __json__(self, topology_dump = False):
+    def __json__(self, topology_dump=False):
         """
         :param topology_dump: Filter to keep only properties require for saving on disk
         """
-        res=[]
+        res = []
         for side in self._nodes:
             res.append({
                 "node_id": side["node"].id,