diff --git a/planetstack/observer/steps/sync_network_slivers.py b/planetstack/observer/steps/sync_network_slivers.py
index a803053..e2556bb 100644
--- a/planetstack/observer/steps/sync_network_slivers.py
+++ b/planetstack/observer/steps/sync_network_slivers.py
@@ -8,7 +8,7 @@
     requested_interval = 3600
     provides=[NetworkSliver]
 
-    def call(self):
+    def call(self, failed=[]):
         networkSlivers = NetworkSliver.objects.all()
         networkSlivers_by_id = {}
         networkSlivers_by_port = {}