diff --git a/main.tf b/main.tf
index 790a44c..6402aa4 100644
--- a/main.tf
+++ b/main.tf
@@ -2,18 +2,18 @@
  * Create S3 bucket with appropriate permissions
  */
 data "template_file" "bucket_policy" {
-  template = "${file("${path.module}/bucket-policy.json")}"
+  template = file("${path.module}/bucket-policy.json")
 
-  vars {
-    bucket_name         = "${var.bucket_name}"
-    deployment_user_arn = "${var.deployment_user_arn}"
+  vars = {
+    bucket_name         = var.bucket_name
+    deployment_user_arn = var.deployment_user_arn
   }
 }
 
 resource "aws_s3_bucket" "hugo" {
-  bucket        = "${var.bucket_name}"
+  bucket        = var.bucket_name
   acl           = "public-read"
-  policy        = "${data.template_file.bucket_policy.rendered}"
+  policy        = data.template_file.bucket_policy.rendered
   force_destroy = true
 
   website {
@@ -21,21 +21,21 @@ resource "aws_s3_bucket" "hugo" {
     error_document = "${var.origin_path}/404.html"
 
     // Routing rule is needed to support hugo friendly urls
-    routing_rules = "${var.routing_rules}"
+    routing_rules = var.routing_rules
   }
 
   cors_rule {
-    allowed_headers = "${var.cors_allowed_headers}"
-    allowed_methods = "${var.cors_allowed_methods}"
-    allowed_origins = "${var.cors_allowed_origins}"
-    expose_headers  = "${var.cors_expose_headers}"
-    max_age_seconds = "${var.cors_max_age_seconds}"
+    allowed_headers = var.cors_allowed_headers
+    allowed_methods = var.cors_allowed_methods
+    allowed_origins = var.cors_allowed_origins
+    expose_headers  = var.cors_expose_headers
+    max_age_seconds = var.cors_max_age_seconds
   }
 }
 
 // Get ACM cert for use with CloudFront
 data "aws_acm_certificate" "cert" {
-  domain = "${var.cert_domain}"
+  domain = var.cert_domain
 }
 
 /*
@@ -43,7 +43,7 @@ data "aws_acm_certificate" "cert" {
  */
 resource "aws_cloudfront_distribution" "hugo" {
   count      = 1
-  depends_on = ["aws_s3_bucket.hugo"]
+  depends_on = [aws_s3_bucket.hugo]
 
   origin {
     custom_origin_config {
@@ -57,20 +57,20 @@ resource "aws_cloudfront_distribution" "hugo" {
     // supports S3 redirects with CloudFront
     domain_name = "${var.bucket_name}.s3-website-${var.aws_region}.amazonaws.com"
 
-    origin_id   = "${var.s3_origin_id}"
-    origin_path = "${var.origin_path}"
+    origin_id   = var.s3_origin_id
+    origin_path = var.origin_path
   }
 
   enabled             = true
   is_ipv6_enabled     = true
   default_root_object = "index.html"
 
-  aliases = ["${var.aliases}"]
+  aliases = var.aliases
 
   default_cache_behavior {
     allowed_methods  = ["GET", "HEAD", "OPTIONS"]
     cached_methods   = ["GET", "HEAD"]
-    target_origin_id = "${var.s3_origin_id}"
+    target_origin_id = var.s3_origin_id
 
     forwarded_values {
       query_string = false
@@ -80,18 +80,18 @@ resource "aws_cloudfront_distribution" "hugo" {
       }
     }
 
-    viewer_protocol_policy = "${var.viewer_protocol_policy}"
+    viewer_protocol_policy = var.viewer_protocol_policy
 
     // Using CloudFront defaults, tune to liking
-    min_ttl     = "${var.cf_min_ttl}"
-    default_ttl = "${var.cf_default_ttl}"
-    max_ttl     = "${var.cf_max_ttl}"
+    min_ttl     = var.cf_min_ttl
+    default_ttl = var.cf_default_ttl
+    max_ttl     = var.cf_max_ttl
   }
 
-  price_class = "${var.cf_price_class}"
+  price_class = var.cf_price_class
 
   viewer_certificate {
-    acm_certificate_arn      = "${data.aws_acm_certificate.cert.arn}"
+    acm_certificate_arn      = data.aws_acm_certificate.cert.arn
     ssl_support_method       = "sni-only"
     minimum_protocol_version = "TLSv1"
   }
diff --git a/outputs.tf b/outputs.tf
index 3efb958..ddd6770 100644
--- a/outputs.tf
+++ b/outputs.tf
@@ -1,11 +1,15 @@
 output "acm_certificate_arn" {
-  value = "${data.aws_acm_certificate.cert.arn}"
+  value = data.aws_acm_certificate.cert.arn
 }
 
 output "cloudfront_hostname" {
-  value = "${aws_cloudfront_distribution.hugo.domain_name}"
+  value = aws_cloudfront_distribution.hugo[0].domain_name
+}
+
+output "cloudfront_zone_id" {
+  value = aws_cloudfront_distribution.hugo[0].hosted_zone_id
 }
 
 output "s3_bucket_arn" {
-  value = "${aws_s3_bucket.hugo.arn}"
+  value = aws_s3_bucket.hugo.arn
 }
diff --git a/vars.tf b/vars.tf
index 4d73454..6078501 100644
--- a/vars.tf
+++ b/vars.tf
@@ -1,87 +1,87 @@
 // Provider vars for authentication
 variable "aliases" {
   description = "List of hostnames to serve site on. E.g. with and without www"
-  type        = "list"
+  type        = list(string)
 }
 
 variable "aws_region" {
-  type    = "string"
+  type    = string
   default = "us-east-1"
 }
 
 variable "bucket_name" {
   description = "Name of bucket to be created in S3. Must be globally unique."
-  type        = "string"
+  type        = string
 }
 
 variable "cert_domain" {
   description = "Domain name on ACM certificate"
-  type        = "string"
+  type        = string
 }
 
 variable "cf_default_ttl" {
   description = "CloudFront default TTL for cachine"
-  type        = "string"
+  type        = string
   default     = "86400"
 }
 
 variable "cf_min_ttl" {
   description = "CloudFront minimum TTL for caching"
-  type        = "string"
+  type        = string
   default     = "0"
 }
 
 variable "cf_max_ttl" {
   description = "CloudFront maximum TTL for caching"
-  type        = "string"
+  type        = string
   default     = "31536000"
 }
 
 variable "cf_price_class" {
   description = "CloudFront price class"
-  type        = "string"
+  type        = string
   default     = "PriceClass_All"
 }
 
 variable "cors_allowed_headers" {
   description = "List of headers allowed in CORS"
-  type        = "list"
+  type        = list(string)
   default     = []
 }
 
 variable "cors_allowed_methods" {
   description = "List of methods allowed in CORS"
-  type        = "list"
+  type        = list(string)
   default     = ["GET"]
 }
 
 variable "cors_allowed_origins" {
   description = "List of origins allowed to make CORS requests"
-  type        = "list"
+  type        = list(string)
   default     = ["https://s3.amazonaws.com"]
 }
 
 variable "cors_expose_headers" {
   description = "List of headers to expose in CORS response"
-  type        = "list"
+  type        = list(string)
   default     = []
 }
 
 variable "cors_max_age_seconds" {
   description = "Specifies time in seconds that browser can cache the response for a preflight request"
-  type        = "string"
+  type        = string
   default     = 3000
 }
 
 variable "origin_path" {
   description = "Path in S3 bucket for hosted files, with leading slash"
-  type        = "string"
+  type        = string
   default     = "/public"
 }
 
 variable "routing_rules" {
   description = "A json array containing routing rules describing redirect behavior and when redirects are applied"
-  type        = "string"
+  type        = string
 
   default = <<EOF
 [{
@@ -93,21 +93,22 @@ variable "routing_rules" {
     }
 }]
 EOF
+
 }
 
 variable "s3_origin_id" {
   description = "Origin ID used in CloudFront"
-  type        = "string"
+  type        = string
   default     = "hugo-s3-origin"
 }
 
 variable "viewer_protocol_policy" {
   description = "One of allow-all, https-only, or redirect-to-https"
-  type        = "string"
+  type        = string
   default     = "redirect-to-https"
 }
 
 variable "deployment_user_arn" {
   description = "ARN for user who is able to put objects into S3 bucket"
-  type        = "string"
-}
\ No newline at end of file
+  type        = string
+}
diff --git a/versions.tf b/versions.tf
new file mode 100644
index 0000000..ac97c6a
--- /dev/null
+++ b/versions.tf
@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}