diff --git a/awx/main/managers.py b/awx/main/managers.py
index f8c2a76997..706947657a 100644
--- a/awx/main/managers.py
+++ b/awx/main/managers.py
@@ -115,10 +115,13 @@ class InstanceManager(models.Manager):
             return node[0]
         raise RuntimeError("No instance found with the current cluster host id")
 
-    def register(self, node_uuid=None, hostname=None, ip_address=None, listener_port=None, node_type='hybrid', defaults=None):
+    def register(self, node_uuid=None, hostname=None, ip_address="", listener_port=None, node_type='hybrid', defaults=None):
         if not hostname:
             hostname = settings.CLUSTER_HOST_ID
 
+        if not ip_address:
+            ip_address = ""
+
         with advisory_lock('instance_registration_%s' % hostname):
             if settings.AWX_AUTO_DEPROVISION_INSTANCES:
                 # detect any instances with the same IP address.