diff --git a/README.md b/README.md
index 8877782..28e3b66 100644
--- a/README.md
+++ b/README.md
@@ -82,12 +82,6 @@ Description: A list of private subnet IDs into which Vault and Consul will be pr
 
 Type: `list(string)`
 
-### <a name="input_ssh_keys"></a> [ssh\_keys](#input\_ssh\_keys)
-
-Description: A list of public ssh keys to add to authorized\_keys files.
-
-Type: `list(string)`
-
 ### <a name="input_ssh_security_group_id"></a> [ssh\_security\_group\_id](#input\_ssh\_security\_group\_id)
 
 Description: Security group ID of a bastion (or other EC2 instance) from which you will be allowed to ssh into Vault and Consul.
@@ -144,6 +138,22 @@ Type: `string`
 
 Default: `""`
 
+### <a name="input_ssh_user"></a> [ssh\_user](#input\_ssh\_user)
+
+Description: User name used for SSH-connections.
+
+Type: `string`
+
+Default: `"ubuntu"`
+
+### <a name="input_ssh_keys"></a> [ssh\_keys](#input\_ssh\_keys)
+
+Description: A list of public ssh keys to add to authorized\_keys files.
+
+Type: `list(string)`
+
+Default: `[]`
+
 ### <a name="input_consul_instance_type"></a> [consul\_instance\_type](#input\_consul\_instance\_type)
 
 Description: The type of EC2 Instance to run in the Consul ASG
diff --git a/data.tf b/data.tf
index aba8a26..2502393 100644
--- a/data.tf
+++ b/data.tf
@@ -1,5 +1 @@
 data "aws_region" "current" {}
-
-data "aws_elb" "vault_elb" {
-  name = module.vault_elb.name
-}
diff --git a/main.tf b/main.tf
index 3d036a5..3c983c6 100644
--- a/main.tf
+++ b/main.tf
@@ -13,7 +13,7 @@ module "vault_cluster" {
     consul_cluster_tag_key   = local.consul_cluster_tag_key
     consul_cluster_tag_value = local.consul_cluster_tag_val
     ssh_keys                 = join("\n", var.ssh_keys)
-    ssh_user                 = "ubuntu"
+    ssh_user                 = var.ssh_user
   }))
 
   vpc_id     = var.vpc_id
@@ -71,7 +71,7 @@ module "vault_elb" {
 
 resource "aws_autoscaling_attachment" "vault" {
   autoscaling_group_name = module.vault_cluster.asg_name
-  elb                    = data.aws_elb.vault_elb.id
+  elb                    = module.vault_elb.id
 }
 
 module "consul_cluster" {
@@ -86,7 +86,7 @@ module "consul_cluster" {
     consul_cluster_tag_key   = local.consul_cluster_tag_key
     consul_cluster_tag_value = local.consul_cluster_tag_val
     ssh_keys                 = join("\n", var.ssh_keys)
-    ssh_user                 = "ubuntu"
+    ssh_user                 = var.ssh_user
   }))
 
   vpc_id     = var.vpc_id
diff --git a/modules/consul-cluster/README.md b/modules/consul-cluster/README.md
index 61659ec..560bcda 100644
--- a/modules/consul-cluster/README.md
+++ b/modules/consul-cluster/README.md
@@ -31,9 +31,9 @@ rules.
 
 | Name | Source | Version |
 |------|--------|---------|
-| <a name="module_attach_security_group"></a> [attach\_security\_group](#module\_attach\_security\_group) | terraform-aws-modules/security-group/aws | 5.1.0 |
+| <a name="module_attach_security_group"></a> [attach\_security\_group](#module\_attach\_security\_group) | terraform-aws-modules/security-group/aws | 5.2.0 |
 | <a name="module_iam_policies"></a> [iam\_policies](#module\_iam\_policies) | github.com/hashicorp/terraform-aws-consul//modules/consul-iam-policies | v0.11.0 |
-| <a name="module_lc_security_group"></a> [lc\_security\_group](#module\_lc\_security\_group) | terraform-aws-modules/security-group/aws | 5.1.0 |
+| <a name="module_lc_security_group"></a> [lc\_security\_group](#module\_lc\_security\_group) | terraform-aws-modules/security-group/aws | 5.2.0 |
 
 ## Resources
 
diff --git a/modules/consul-cluster/main.tf b/modules/consul-cluster/main.tf
index 8b6e2c1..9a5be0c 100644
--- a/modules/consul-cluster/main.tf
+++ b/modules/consul-cluster/main.tf
@@ -71,7 +71,7 @@ resource "aws_launch_template" "launch_template" {
   block_device_mappings {
     device_name = "/dev/sda1"
     ebs {
-      volume_size = var.root_volume_size
+      volume_size           = var.root_volume_size
       delete_on_termination = var.root_volume_delete_on_termination
       volume_type           = var.root_volume_type
     }
diff --git a/modules/consul-cluster/security-groups.tf b/modules/consul-cluster/security-groups.tf
index 4bd085a..cac44e0 100644
--- a/modules/consul-cluster/security-groups.tf
+++ b/modules/consul-cluster/security-groups.tf
@@ -1,6 +1,6 @@
 module "attach_security_group" {
   source  = "terraform-aws-modules/security-group/aws"
-  version = "5.1.0"
+  version = "5.2.0"
 
   name        = "${var.cluster_name}-att"
   description = "Null Placeholder security group for other instances to  use as destination to access ${var.cluster_name}"
@@ -38,7 +38,7 @@ module "attach_security_group" {
 
 module "lc_security_group" {
   source  = "terraform-aws-modules/security-group/aws"
-  version = "5.1.0"
+  version = "5.2.0"
 
   name        = var.cluster_name
   description = "Security group for the ${var.cluster_name} launch configuration"
diff --git a/modules/vault-cluster/README.md b/modules/vault-cluster/README.md
index 1d62025..354b415 100644
--- a/modules/vault-cluster/README.md
+++ b/modules/vault-cluster/README.md
@@ -51,8 +51,8 @@ machines.
 
 | Name | Source | Version |
 |------|--------|---------|
-| <a name="module_attach_security_group"></a> [attach\_security\_group](#module\_attach\_security\_group) | terraform-aws-modules/security-group/aws | 5.1.0 |
-| <a name="module_lc_security_group"></a> [lc\_security\_group](#module\_lc\_security\_group) | terraform-aws-modules/security-group/aws | 5.1.0 |
+| <a name="module_attach_security_group"></a> [attach\_security\_group](#module\_attach\_security\_group) | terraform-aws-modules/security-group/aws | 5.2.0 |
+| <a name="module_lc_security_group"></a> [lc\_security\_group](#module\_lc\_security\_group) | terraform-aws-modules/security-group/aws | 5.2.0 |
 
 ## Resources
 
diff --git a/modules/vault-cluster/main.tf b/modules/vault-cluster/main.tf
index 50cec40..febb332 100644
--- a/modules/vault-cluster/main.tf
+++ b/modules/vault-cluster/main.tf
@@ -67,7 +67,7 @@ resource "aws_launch_template" "launch_template" {
   block_device_mappings {
     device_name = "/dev/sda1"
     ebs {
-      volume_size = var.root_volume_size
+      volume_size           = var.root_volume_size
       delete_on_termination = var.root_volume_delete_on_termination
       volume_type           = var.root_volume_type
     }
diff --git a/modules/vault-cluster/security-groups.tf b/modules/vault-cluster/security-groups.tf
index 991a2ff..50d779a 100644
--- a/modules/vault-cluster/security-groups.tf
+++ b/modules/vault-cluster/security-groups.tf
@@ -1,6 +1,6 @@
 module "attach_security_group" {
   source  = "terraform-aws-modules/security-group/aws"
-  version = "5.1.0"
+  version = "5.2.0"
 
   name        = "${var.cluster_name}-att"
   description = "Null Placeholder security group for other instances to  use as destination to access ${var.cluster_name}"
@@ -38,7 +38,7 @@ module "attach_security_group" {
 
 module "lc_security_group" {
   source  = "terraform-aws-modules/security-group/aws"
-  version = "5.1.0"
+  version = "5.2.0"
 
   name        = var.cluster_name
   description = "Security group for the ${var.cluster_name} launch configuration"
diff --git a/user-data/consul.sh.tftpl b/user-data/consul.sh.tftpl
index 4c69e8a..3c3a968 100755
--- a/user-data/consul.sh.tftpl
+++ b/user-data/consul.sh.tftpl
@@ -12,7 +12,7 @@ set -x
 exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
 
 # Add SSH keys
-printf "${ssh_keys}\n" > "/home/${ssh_user}/.ssh/authorized_keys"
+printf "${ssh_keys}\n" >> "/home/${ssh_user}/.ssh/authorized_keys"
 chmod 600 "/home/${ssh_user}/.ssh/authorized_keys"
 chown ${ssh_user}:${ssh_user} "/home/${ssh_user}/.ssh/authorized_keys"
 
diff --git a/user-data/vault.sh.tftpl b/user-data/vault.sh.tftpl
index 28f8371..07e67ca 100755
--- a/user-data/vault.sh.tftpl
+++ b/user-data/vault.sh.tftpl
@@ -13,7 +13,7 @@ set -x
 exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
 
 # Add SSH keys
-printf "${ssh_keys}\n" > "/home/${ssh_user}/.ssh/authorized_keys"
+printf "${ssh_keys}\n" >> "/home/${ssh_user}/.ssh/authorized_keys"
 chmod 600 "/home/${ssh_user}/.ssh/authorized_keys"
 chown ${ssh_user}:${ssh_user} "/home/${ssh_user}/.ssh/authorized_keys"
 
diff --git a/variables.tf b/variables.tf
index d978adf..9ce4e5d 100644
--- a/variables.tf
+++ b/variables.tf
@@ -43,9 +43,16 @@ variable "vault_route53_public_dns_name" {
   type        = string
 }
 
+variable "ssh_user" {
+  description = "User name used for SSH-connections."
+  type        = string
+  default     = "ubuntu"
+}
+
 variable "ssh_keys" {
   description = "A list of public ssh keys to add to authorized_keys files."
   type        = list(string)
+  default     = []
 }
 
 variable "consul_instance_type" {