diff --git a/aws-experiment-launch/utils/utils.py b/aws-experiment-launch/utils/utils.py
index 7a8c31ce5..9a18dbe59 100644
--- a/aws-experiment-launch/utils/utils.py
+++ b/aws-experiment-launch/utils/utils.py
@@ -38,13 +38,18 @@ def create_ec2_client(region_number, region_config):
     session = boto3.Session(region_name=region_name)
     return session.client('ec2')
 
-def collect_public_ips(region_number, node_name_tag, region_config):
-    ec2_client = create_ec2_client(region_number, region_config)
+def collect_public_ips_from_ec2_client(ec2_client, node_name_tag):
     filters = [{'Name': 'tag:Name','Values': [node_name_tag]}]
     response = ec2_client.describe_instances(Filters=filters)
     ip_list = []
-    for reservation in response[u'Reservations']:
-        ip_list.extend(instance['PublicIpAddress'] for instance in reservation['Instances'])
+    if response.get('Reservations'):
+        for reservation in response[u'Reservations']:
+            ip_list.extend(instance['PublicIpAddress'] for instance in reservation['Instances'] if instance.get('PublicIpAddress'))
+    return ip_list
+
+def collect_public_ips(region_number, node_name_tag, region_config):
+    ec2_client = create_ec2_client(region_number, region_config)
+    ip_list = collect_public_ips_from_ec2_client(ec2_client, node_name_tag)
     return ip_list
 
 def generate_distribution_config2(region_number, node_name_tag, region_config,