diff --git a/planetstack/observer/openstacksyncstep.py b/planetstack/observer/openstacksyncstep.py
index 515ff09..4f2a260 100644
--- a/planetstack/observer/openstacksyncstep.py
+++ b/planetstack/observer/openstacksyncstep.py
@@ -10,5 +10,5 @@
         SyncStep.__init__(self, **args)
         return
 
-    def __call__(self):
-        return self.call()
+    def __call__(self, **args):
+        return self.call(**args)
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 = {}
diff --git a/planetstack/observer/syncstep.py b/planetstack/observer/syncstep.py
index 8e8d4fc..75f575c 100644
--- a/planetstack/observer/syncstep.py
+++ b/planetstack/observer/syncstep.py
@@ -59,5 +59,5 @@
                     failed.append(o)
         return failed
 
-    def __call__(self):
-        return self.call()
+    def __call__(self, **args):
+        return self.call(**args)