diff --git a/CHANGELOG.md b/CHANGELOG.md
index 856055d..32df592 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
+## 1.0.0
+ENHANCEMENTS:
+* Upgrade TF to version 12 ([#4](https://github.com/zoitech/terraform-aws-cloudfront/issues/4))
+
 ## 0.0.2 (Unreleased)
 ENHANCEMENTS:
 
 * Add custom response error referrenced in issue ([#3](https://github.com/zoitech/terraform-aws-cloudfront/issues/3))
-* Add default_cache_behavior ( header )
\ No newline at end of file
+* Add default_cache_behavior ( header )
diff --git a/README.md b/README.md
index fbfd966..dc41797 100644
--- a/README.md
+++ b/README.md
@@ -57,7 +57,7 @@ module "my_cloudfront" {
   restriction_type = "none"
 
   # Certificate
-  acm_certificate_arn      = "${data.aws_acm_certificate.my_acm_certificate.arn}"
+  acm_certificate_arn      = data.aws_acm_certificate.my_acm_certificate.arn
   minimum_protocol_version = "TLSv1.1_2016"
   ssl_support_method       = "sni-only"
 }
@@ -66,4 +66,4 @@ module "my_cloudfront" {
 #### Outputs
 The following outputs are possible:
 * domain_name  (The domain name corresponding to the distribution. For example: d604721fxaaqy9.cloudfront.net)
-* hosted_zone_id (The CloudFront Route 53 zone ID that can be used to route an Alias Resource Record Set to. This attribute is simply an alias for the zone ID Z2FDTNDATAQYW2.)
\ No newline at end of file
+* hosted_zone_id (The CloudFront Route 53 zone ID that can be used to route an Alias Resource Record Set to. This attribute is simply an alias for the zone ID Z2FDTNDATAQYW2.)
diff --git a/cloudfront.tf b/cloudfront.tf
index f95003a..4f76f74 100644
--- a/cloudfront.tf
+++ b/cloudfront.tf
@@ -1,33 +1,46 @@
 resource "aws_cloudfront_distribution" "distribution" {
   origin {
-    domain_name = "${var.dns_domain_name}"
-    origin_id   = "${var.origin_id}"
-
+    domain_name = var.dns_domain_name
+    origin_id   = var.origin_id
     # s3_origin_config {
     #   origin_access_identity = "origin-access-identity/cloudfront/ABCDEFG1234567"
     # }
   }
 
-  enabled             = "${var.state_enabled}"
-  is_ipv6_enabled     = "${var.is_ipv6_enabled}"
-  comment             = "${var.comment}"
-  default_root_object = "${var.default_root_object}"
+  enabled             = var.state_enabled
+  is_ipv6_enabled     = var.is_ipv6_enabled
+  comment             = var.comment
+  default_root_object = var.default_root_object
 
   logging_config {
-    include_cookies = "${var.logging_config_include_cookies}" #The logging configuration that controls how logs are written to your distribution (maximum one).
-    bucket          = "${var.logging_config_bucket}"
-    prefix          = "${var.logging_config_prefix}"
+    include_cookies = var.logging_config_include_cookies #The logging configuration that controls how logs are written to your distribution (maximum one).
+    bucket          = var.logging_config_bucket
+    prefix          = var.logging_config_prefix
   }
- 
-  aliases = "${var.aliases}" #list
+
+  aliases = var.aliases #list
 
   # Custom Error response
-  custom_error_response = ["${var.custom_error_response}" ] #list
-  
+  dynamic "custom_error_response" {
+    for_each = [for i in var.custom_error_response : {
+      error_caching_min_ttl = i.error_caching_min_ttl
+      error_code            = i.error_code
+      response_code         = i.response_code
+      response_page_path    = i.response_page_path
+    }]
+
+    content {
+      error_caching_min_ttl = custom_error_response.value.error_caching_min_ttl
+      error_code            = custom_error_response.value.error_code
+      response_code         = custom_error_response.value.response_code
+      response_page_path    = custom_error_response.value.response_page_path
+    }
+  }
+
   default_cache_behavior {
-    allowed_methods  = "${var.default_cache_behavior_allowed_methods}" #list
-    cached_methods   = "${var.default_cache_behavior_cached_methods}"  #list
-    target_origin_id = "${var.target_origin_id}"
+    allowed_methods  = var.default_cache_behavior_allowed_methods #list
+    cached_methods   = var.default_cache_behavior_cached_methods  #list
+    target_origin_id = var.target_origin_id
 
     forwarded_values {
       query_string = false
@@ -36,27 +49,28 @@ resource "aws_cloudfront_distribution" "distribution" {
         forward = "none"
       }
 
-      headers = "${var.default_cache_behavior_forwarded_values_headers}" #list
+      headers = var.default_cache_behavior_forwarded_values_headers #list
     }
 
-    viewer_protocol_policy = "${var.viewer_protocol_policy}"
+    viewer_protocol_policy = var.viewer_protocol_policy
     min_ttl                = 0
     default_ttl            = 3600
     max_ttl                = 86400
   }
 
-  price_class = "${var.price_class}"
+  price_class = var.price_class
 
   restrictions {
     geo_restriction {
-      restriction_type = "${var.restriction_type}"
-      locations        = "${var.restriction_locations}"
+      restriction_type = var.restriction_type
+      locations        = var.restriction_locations
     }
   }
 
   viewer_certificate {
-    acm_certificate_arn = "${var.acm_certificate_arn}"
-    minimum_protocol_version = "${var.minimum_protocol_version}"
-    ssl_support_method = "${var.ssl_support_method}"
+    acm_certificate_arn      = var.acm_certificate_arn
+    minimum_protocol_version = var.minimum_protocol_version
+    ssl_support_method       = var.ssl_support_method
   }
 }
+
diff --git a/outputs.tf b/outputs.tf
index c406b7c..89fd95e 100644
--- a/outputs.tf
+++ b/outputs.tf
@@ -1,6 +1,8 @@
 output "domain_name" {
-  value = "${aws_cloudfront_distribution.distribution.domain_name}"
+  value = aws_cloudfront_distribution.distribution.domain_name
 }
+
 output "hosted_zone_id" {
-  value = "${aws_cloudfront_distribution.distribution.hosted_zone_id}"
-}
\ No newline at end of file
+  value = aws_cloudfront_distribution.distribution.hosted_zone_id
+}
+
diff --git a/provider.tf b/provider.tf
new file mode 100644
index 0000000..dc58d9a
--- /dev/null
+++ b/provider.tf
@@ -0,0 +1,3 @@
+provider "aws" {
+  region = var.region
+}
diff --git a/variables.tf b/variables.tf
index 4940168..26bc2a6 100644
--- a/variables.tf
+++ b/variables.tf
@@ -44,22 +44,22 @@ variable "logging_config_prefix" {
 }
 
 variable "aliases" {
-  type        = "list"
+  type        = list(string)
   description = "(Optional) - Extra CNAMEs (alternate domain names), if any, for this distribution."
 }
 
 variable "default_cache_behavior_allowed_methods" {
-  type        = "list"
+  type        = list(string)
   description = "(Required) - Controls which HTTP methods CloudFront processes and forwards to your Amazon S3 bucket or your custom origin."
 }
 
 variable "default_cache_behavior_cached_methods" {
-  type        = "list"
+  type        = list(string)
   description = "(Required) - Controls whether CloudFront caches the response to requests using the specified HTTP methods."
 }
 
 variable "default_cache_behavior_forwarded_values_headers" {
-  type        = "list"
+  type        = list(string)
   description = "(Required) - Specifies the Headers, if any, that you want CloudFront to vary upon for this cache behavior. Specify * to include all headers."
 }
 
@@ -81,7 +81,7 @@ variable "restriction_type" {
 }
 
 variable "restriction_locations" {
-  type        = "list"
+  type        = list(string)
   description = "(Optional) - The ISO 3166-1-alpha-2 codes for which you want CloudFront either to distribute your content (whitelist) or not distribute your content (blacklist)."
   default     = []
 }
@@ -91,14 +91,20 @@ variable "acm_certificate_arn" {
 }
 
 variable "minimum_protocol_version" {
- description = "The minimum version of the SSL protocol that you want CloudFront to use for HTTPS connections. One of SSLv3, TLSv1, TLSv1_2016, TLSv1.1_2016 or TLSv1.2_2018. Default: TLSv1. NOTE: If you are using a custom certificate (specified with acm_certificate_arn or iam_certificate_id), and have specified sni-only in ssl_support_method, TLSv1 or later must be specified. If you have specified vip in ssl_support_method, only SSLv3 or TLSv1 can be specified. If you have specified cloudfront_default_certificate, TLSv1 must be specified."
-} 
+  description = "The minimum version of the SSL protocol that you want CloudFront to use for HTTPS connections. One of SSLv3, TLSv1, TLSv1_2016, TLSv1.1_2016 or TLSv1.2_2018. Default: TLSv1. NOTE: If you are using a custom certificate (specified with acm_certificate_arn or iam_certificate_id), and have specified sni-only in ssl_support_method, TLSv1 or later must be specified. If you have specified vip in ssl_support_method, only SSLv3 or TLSv1 can be specified. If you have specified cloudfront_default_certificate, TLSv1 must be specified."
+}
+
 variable "ssl_support_method" {
- description = "Specifies how you want CloudFront to serve HTTPS requests. One of vip or sni-only. Required if you specify acm_certificate_arn or iam_certificate_id. NOTE: vip causes CloudFront to use a dedicated IP address and may incur extra charges."
-} 
+  description = "Specifies how you want CloudFront to serve HTTPS requests. One of vip or sni-only. Required if you specify acm_certificate_arn or iam_certificate_id. NOTE: vip causes CloudFront to use a dedicated IP address and may incur extra charges."
+}
 
 variable "custom_error_response" {
   description = "(Optional) - One or more custom error response elements (multiples allowed)."
-  type = "list"
-  default = []
-}
\ No newline at end of file
+  type        = any
+  default     = []
+}
+
+variable "region" {
+  description = "region"
+  default     = "eu-west-1"
+}
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"
+}