diff --git a/terraform/aws/elb/main.tf b/terraform/aws/elb/main.tf
index d0c3c52..9630948 100644
--- a/terraform/aws/elb/main.tf
+++ b/terraform/aws/elb/main.tf
@@ -1,7 +1,11 @@
 variable "elb_name" { default = "kube-master" }
 variable "health_check_target" { default = "HTTP:8080/healthz" }
-variable "instances" {}
-variable "subnets" {}
+variable "instances" {
+    type = "list"
+}
+variable "subnets" {
+    type = "list"
+}
 variable "security_groups" {}
 
 resource "aws_elb" "kube_master" {
diff --git a/terraform/aws/public-cloud/etcd_discovery_url.txt b/terraform/aws/public-cloud/etcd_discovery_url.txt
index 6fe5f6a..7bafcfd 100644
--- a/terraform/aws/public-cloud/etcd_discovery_url.txt
+++ b/terraform/aws/public-cloud/etcd_discovery_url.txt
@@ -1 +1 @@
-https://discovery.etcd.io/5a6cb41d2a91517447cb738d7e2cf898
\ No newline at end of file
+https://discovery.etcd.io/94584ca1ffd519c16bdae0f082b70733
\ No newline at end of file
diff --git a/terraform/aws/public-cloud/main.tf b/terraform/aws/public-cloud/main.tf
index b90f179..db029c7 100644
--- a/terraform/aws/public-cloud/main.tf
+++ b/terraform/aws/public-cloud/main.tf
@@ -67,8 +67,8 @@ module "kube_master_certs" {
   ca_cert_pem           = "${module.ca.ca_cert_pem}"
   ca_private_key_pem    = "${module.ca.ca_private_key_pem}"
   ip_addresses          = "${concat(aws_instance.master.*.private_ip, aws_instance.master.*.public_ip)}"
-  dns_names             = "${compact(module.master_elb.elb_dns_name)}"
-  deploy_ssh_hosts      = "${compact(aws_instance.master.*.public_ip)}"
+  dns_names             = ["${module.master_elb.elb_dns_name}"]
+  deploy_ssh_hosts      = ["${aws_instance.master.*.public_ip}"]
   master_count          = "${var.masters}"
   validity_period_hours = "8760"
   early_renewal_hours   = "720"
@@ -104,8 +104,8 @@ module "docker_daemon_certs" {
   deploy_ssh_hosts      = "${concat(aws_instance.master.*.public_ip, aws_instance.worker.*.public_ip)}"
   docker_daemon_count   = "${var.masters + var.workers}"
   private_key           = "${tls_private_key.ssh.private_key_pem}"
-  validity_period_hours = 8760
-  early_renewal_hours   = 720
+  validity_period_hours = "8760"
+  early_renewal_hours   = "720"
   user                  = "core"
 }
 
@@ -117,8 +117,8 @@ module "docker_client_certs" {
   deploy_ssh_hosts      = "${concat(aws_instance.master.*.public_ip, aws_instance.worker.*.public_ip)}"
   docker_client_count   = "${var.masters + var.workers}"
   private_key           = "${tls_private_key.ssh.private_key_pem}"
-  validity_period_hours = 8760
-  early_renewal_hours   = 720
+  validity_period_hours = "8760"
+  early_renewal_hours   = "720"
   user                  = "core"
 }
 
diff --git a/terraform/aws/public-cloud/masters.tf b/terraform/aws/public-cloud/masters.tf
index 08f6c4c..02e68dc 100644
--- a/terraform/aws/public-cloud/masters.tf
+++ b/terraform/aws/public-cloud/masters.tf
@@ -60,8 +60,8 @@ resource "aws_instance" "master" {
 module "master_elb" {
   source             = "../elb"
   security_groups    = "${module.sg-default.security_group_id}"
-  instances          = "${compact(aws_instance.master.*.id)}"
-  subnets            = "${compact(aws_instance.master.*.subnet_id)}"
+  instances          = [ "${aws_instance.master.*.id}" ]
+  subnets            = [ "${aws_instance.master.*.subnet_id}" ]
 }
 
 output "master_ips" {