diff --git a/CHANGELOG.md b/CHANGELOG.md
index 62f591a..8517655 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,10 @@ and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### CHANGED
+
+- Upgraded for usage with terraform-0.12.x [#6]
+
 
 ## [0.1.1] - 2019-06-14
 
@@ -26,3 +30,4 @@ and this project adheres to
 [0.1.0]: https://github.com/terraform-google-modules/terraform-google-service-accounts/releases/tag/v0.1.0
 [#3]: https://github.com/terraform-google-modules/terraform-google-service-accounts/pull/3
 [#1]: https://github.com/terraform-google-modules/terraform-google-service-accounts/pull/1
+[#6]: https://github.com/terraform-google-modules/terraform-google-service-accounts/pull/6
\ No newline at end of file
diff --git a/Gemfile b/Gemfile
index 4dbdea2..6dc7c95 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,5 +15,5 @@
 ruby '2.5.3'
 
 source 'https://rubygems.org/' do
-  gem 'kitchen-terraform', '~> 4.8'
+  gem 'kitchen-terraform', '~> 4.9'
 end
diff --git a/Makefile b/Makefile
index 730d0ae..1ad0d6a 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@ SHELL := /usr/bin/env bash
 # Docker build config variables
 CREDENTIALS_PATH 			?= /cft/workdir/credentials.json
 DOCKER_ORG 				:= gcr.io/cloud-foundation-cicd
-DOCKER_TAG_BASE_KITCHEN_TERRAFORM 	?= 1.0.1
+DOCKER_TAG_BASE_KITCHEN_TERRAFORM 	?= 2.3.0
 DOCKER_REPO_BASE_KITCHEN_TERRAFORM 	:= ${DOCKER_ORG}/cft/kitchen-terraform:${DOCKER_TAG_BASE_KITCHEN_TERRAFORM}
 
 # All is the first target in the file so it will get picked up when you just run 'make' on its own
@@ -30,7 +30,7 @@ all: check generate_docs
 
 # Run all available linters
 .PHONY: check
-check: check_shell check_python check_golang check_terraform check_docker check_base_files test_check_headers check_headers check_trailing_whitespace
+check: check_shell check_python check_golang check_terraform check_base_files test_check_headers check_headers check_trailing_whitespace
 
 # The .PHONY directive tells make that this isn't a real target and so
 # the presence of a file named 'check_shell' won't cause this target to stop
@@ -95,7 +95,7 @@ docker_run:
 		-e GOOGLE_APPLICATION_CREDENTIALS=${CREDENTIALS_PATH} \
 		-v $(CURDIR):/cft/workdir \
 		${DOCKER_REPO_BASE_KITCHEN_TERRAFORM} \
-		/bin/bash -c "source test/ci_integration.sh && setup_environment && exec /bin/bash"
+		/bin/bash -c "cd /cft/workdir && source test/ci_integration.sh && setup_environment && exec /bin/bash"
 
 .PHONY: docker_create
 docker_create:
@@ -105,7 +105,7 @@ docker_create:
 		-e GOOGLE_APPLICATION_CREDENTIALS=${CREDENTIALS_PATH} \
 		-v $(CURDIR):/cft/workdir \
 		${DOCKER_REPO_BASE_KITCHEN_TERRAFORM} \
-		/bin/bash -c "source test/ci_integration.sh && setup_environment && kitchen create"
+		/bin/bash -c "cd /cft/workdir && source test/ci_integration.sh && setup_environment && kitchen create"
 
 .PHONY: docker_converge
 docker_converge:
@@ -115,7 +115,7 @@ docker_converge:
 		-e GOOGLE_APPLICATION_CREDENTIALS=${CREDENTIALS_PATH} \
 		-v $(CURDIR):/cft/workdir \
 		${DOCKER_REPO_BASE_KITCHEN_TERRAFORM} \
-		/bin/bash -c "source test/ci_integration.sh && setup_environment && kitchen converge"
+		/bin/bash -c "cd /cft/workdir && source test/ci_integration.sh && setup_environment && kitchen converge"
 
 .PHONY: docker_verify
 docker_verify:
@@ -125,7 +125,7 @@ docker_verify:
 		-e GOOGLE_APPLICATION_CREDENTIALS=${CREDENTIALS_PATH} \
 		-v $(CURDIR):/cft/workdir \
 		${DOCKER_REPO_BASE_KITCHEN_TERRAFORM} \
-		/bin/bash -c "source test/ci_integration.sh && setup_environment && kitchen verify"
+		/bin/bash -c "cd /cft/workdir && source test/ci_integration.sh && setup_environment && kitchen verify"
 
 .PHONY: docker_destroy
 docker_destroy:
@@ -135,7 +135,7 @@ docker_destroy:
 		-e GOOGLE_APPLICATION_CREDENTIALS=${CREDENTIALS_PATH} \
 		-v $(CURDIR):/cft/workdir \
 		${DOCKER_REPO_BASE_KITCHEN_TERRAFORM} \
-		/bin/bash -c "source test/ci_integration.sh && setup_environment && kitchen destroy"
+		/bin/bash -c "cd /cft/workdir && source test/ci_integration.sh && setup_environment && kitchen destroy"
 
 .PHONY: test_integration_docker
 test_integration_docker:
@@ -145,4 +145,4 @@ test_integration_docker:
 		-e GOOGLE_APPLICATION_CREDENTIALS=${CREDENTIALS_PATH} \
 		-v $(CURDIR):/cft/workdir \
 		${DOCKER_REPO_BASE_KITCHEN_TERRAFORM} \
-		make test_integration
+		/bin/bash -c "cd /cft/workdir && source test/ci_integration.sh && setup_environment && make test_integration"
diff --git a/README.md b/README.md
index 2efbc6a..6151b80 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,12 @@ The resources/services/activations/deletions that this module will create/trigge
 - two optional organization-level IAM bindings per service account, to enable the service accounts to create and manage Shared VPC networks
 - one optional service account key per service account
 
+## Compatibility
+
+ This module is meant for use with Terraform 0.12. If you haven't [upgraded](https://www.terraform.io/upgrade-guides/0-12.html)
+  and need a Terraform 0.11.x-compatible version of this module, the last released version intended for
+  Terraform 0.11.x is [0.1.1](https://registry.terraform.io/modules/terraform-google-modules/service-accounts/google/0.1.1).
+
 ## Usage
 
 Basic usage of this module is as follows:
@@ -67,7 +73,7 @@ These sections describe requirements for using this module.
 
 The following dependencies must be available:
 
-- [Terraform][terraform] v0.11
+- [Terraform][terraform] v0.12
 - [Terraform Provider for GCP][terraform-provider-gcp] plugin >= v2.0
 
 ### IAM
diff --git a/examples/multiple_service_accounts/main.tf b/examples/multiple_service_accounts/main.tf
index 87a544d..81968fa 100644
--- a/examples/multiple_service_accounts/main.tf
+++ b/examples/multiple_service_accounts/main.tf
@@ -20,7 +20,7 @@ provider "google" {
 
 module "service_accounts" {
   source        = "../.."
-  project_id    = "${var.project_id}"
+  project_id    = var.project_id
   prefix        = ""
   names         = ["test-first", "test-second"]
   generate_keys = true
@@ -30,3 +30,4 @@ module "service_accounts" {
     "${var.project_id}=>roles/storage.objectViewer",
   ]
 }
+
diff --git a/examples/multiple_service_accounts/outputs.tf b/examples/multiple_service_accounts/outputs.tf
index 141bc51..44f1014 100644
--- a/examples/multiple_service_accounts/outputs.tf
+++ b/examples/multiple_service_accounts/outputs.tf
@@ -16,15 +16,16 @@
 
 output "emails" {
   description = "The service account emails."
-  value       = "${values(module.service_accounts.emails)}"
+  value       = values(module.service_accounts.emails)
 }
 
 output "iam_emails" {
   description = "The service account IAM-format emails."
-  value       = "${values(module.service_accounts.iam_emails)}"
+  value       = values(module.service_accounts.iam_emails)
 }
 
 output "keys" {
   description = "The service account keys."
-  value       = "${module.service_accounts.keys}"
+  value       = module.service_accounts.keys
 }
+
diff --git a/examples/multiple_service_accounts/variables.tf b/examples/multiple_service_accounts/variables.tf
index b6df58e..189ff9d 100644
--- a/examples/multiple_service_accounts/variables.tf
+++ b/examples/multiple_service_accounts/variables.tf
@@ -16,5 +16,6 @@
 
 variable "project_id" {
   description = "The ID of the project in which to provision resources."
-  type        = "string"
+  type        = string
 }
+
diff --git a/examples/multiple_service_accounts/versions.tf b/examples/multiple_service_accounts/versions.tf
new file mode 100644
index 0000000..2970427
--- /dev/null
+++ b/examples/multiple_service_accounts/versions.tf
@@ -0,0 +1,19 @@
+/**
+ * Copyright 2019 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+terraform {
+  required_version = ">= 0.12"
+}
diff --git a/examples/single_service_account/main.tf b/examples/single_service_account/main.tf
index efb2e61..a0dd221 100644
--- a/examples/single_service_account/main.tf
+++ b/examples/single_service_account/main.tf
@@ -20,8 +20,9 @@ provider "google" {
 
 module "service_accounts" {
   source        = "../.."
-  project_id    = "${var.project_id}"
-  prefix        = "${var.prefix}"
+  project_id    = var.project_id
+  prefix        = var.prefix
   names         = ["single-account"]
   project_roles = ["${var.project_id}=>roles/viewer"]
 }
+
diff --git a/examples/single_service_account/outputs.tf b/examples/single_service_account/outputs.tf
index a216c75..c95e614 100644
--- a/examples/single_service_account/outputs.tf
+++ b/examples/single_service_account/outputs.tf
@@ -16,10 +16,11 @@
 
 output "email" {
   description = "The service account email."
-  value       = "${module.service_accounts.email}"
+  value       = module.service_accounts.email
 }
 
 output "iam_email" {
   description = "The service account IAM-format email."
-  value       = "${module.service_accounts.iam_email}"
+  value       = module.service_accounts.iam_email
 }
+
diff --git a/examples/single_service_account/variables.tf b/examples/single_service_account/variables.tf
index 206318d..7083fec 100644
--- a/examples/single_service_account/variables.tf
+++ b/examples/single_service_account/variables.tf
@@ -16,10 +16,12 @@
 
 variable "project_id" {
   description = "The ID of the project in which to provision resources."
-  type        = "string"
+  type        = string
 }
 
 variable "prefix" {
+  type        = string
   description = "Prefix applied to service account names."
   default     = ""
 }
+
diff --git a/examples/single_service_account/versions.tf b/examples/single_service_account/versions.tf
new file mode 100644
index 0000000..2970427
--- /dev/null
+++ b/examples/single_service_account/versions.tf
@@ -0,0 +1,19 @@
+/**
+ * Copyright 2019 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+terraform {
+  required_version = ">= 0.12"
+}
diff --git a/main.tf b/main.tf
index d994c92..7b38a3e 100644
--- a/main.tf
+++ b/main.tf
@@ -15,73 +15,82 @@
  */
 
 locals {
-  account_billing = "${var.grant_billing_role && var.billing_account_id != ""}"
-  org_billing     = "${var.grant_billing_role && var.billing_account_id == "" && var.org_id != ""}"
-  prefix          = "${var.prefix != "" ? "${var.prefix}-" : ""}"
-  xpn             = "${var.grant_xpn_roles && var.org_id != ""}"
+  account_billing = var.grant_billing_role && var.billing_account_id != ""
+  org_billing     = var.grant_billing_role && var.billing_account_id == "" && var.org_id != ""
+  prefix          = var.prefix != "" ? "${var.prefix}-" : ""
+  xpn             = var.grant_xpn_roles && var.org_id != ""
 }
 
 # create service accounts
 resource "google_service_account" "service_accounts" {
-  count        = "${length(var.names)}"
+  count        = length(var.names)
   account_id   = "${local.prefix}${lower(element(var.names, count.index))}"
   display_name = "Terraform-managed service account"
-  project      = "${var.project_id}"
+  project      = var.project_id
 }
 
 # common roles
 resource "google_project_iam_member" "project-roles" {
-  count = "${length(var.project_roles) * length(var.names)}"
+  count = length(var.project_roles) * length(var.names)
 
-  project = "${element(
-    split("=>", element(var.project_roles, count.index % length(var.project_roles))
-  ), 0)}"
+  project = element(
+    split(
+      "=>",
+      element(var.project_roles, count.index % length(var.project_roles)),
+    ),
+    0,
+  )
 
-  role = "${element(
-    split("=>", element(var.project_roles, count.index % length(var.project_roles))
-  ), 1)}"
+  role = element(
+    split(
+      "=>",
+      element(var.project_roles, count.index % length(var.project_roles)),
+    ),
+    1,
+  )
 
   member = "serviceAccount:${element(
     google_service_account.service_accounts.*.email,
-    count.index / length(var.project_roles)
+    floor(count.index / length(var.project_roles)),
   )}"
 }
 
 # conditionally assign billing user role at the org level
 resource "google_organization_iam_member" "billing_user" {
-  count  = "${local.org_billing ? length(var.names) : 0}"
-  org_id = "${var.org_id}"
+  count  = local.org_billing ? length(var.names) : 0
+  org_id = var.org_id
   role   = "roles/billing.user"
-  member = "serviceAccount:${element(google_service_account.service_accounts.*.email, count.index)}"
+  member = "serviceAccount:${google_service_account.service_accounts[count.index].email}"
 }
 
 # conditionally assign billing user role on a specific billing account
 resource "google_billing_account_iam_member" "billing_user" {
-  count              = "${local.account_billing ? length(var.names) : 0}"
-  billing_account_id = "${var.billing_account_id}"
+  count              = local.account_billing ? length(var.names) : 0
+  billing_account_id = var.billing_account_id
   role               = "roles/billing.user"
-  member             = "serviceAccount:${element(google_service_account.service_accounts.*.email, count.index)}"
+  member             = "serviceAccount:${google_service_account.service_accounts[count.index].email}"
 }
 
 # conditionally assign roles for shared VPC
 # ref: https://cloud.google.com/vpc/docs/shared-vpc
 
 resource "google_organization_iam_member" "xpn_admin" {
-  count  = "${local.xpn ? length(var.names) : 0}"
-  org_id = "${var.org_id}"
+  count  = local.xpn ? length(var.names) : 0
+  org_id = var.org_id
   role   = "roles/compute.xpnAdmin"
-  member = "serviceAccount:${element(google_service_account.service_accounts.*.email, count.index)}"
+  member = "serviceAccount:${google_service_account.service_accounts[count.index].email}"
 }
 
 resource "google_organization_iam_member" "organization_viewer" {
-  count  = "${local.xpn ? length(var.names) : 0}"
-  org_id = "${var.org_id}"
+  count  = local.xpn ? length(var.names) : 0
+  org_id = var.org_id
   role   = "roles/resourcemanager.organizationViewer"
-  member = "serviceAccount:${element(google_service_account.service_accounts.*.email, count.index)}"
+  member = "serviceAccount:${google_service_account.service_accounts[count.index].email}"
 }
 
 # keys
 resource "google_service_account_key" "keys" {
-  count              = "${var.generate_keys ? length(var.names) : 0}"
-  service_account_id = "${element(google_service_account.service_accounts.*.email, count.index)}"
+  count              = var.generate_keys ? length(var.names) : 0
+  service_account_id = google_service_account.service_accounts[count.index].email
 }
+
diff --git a/outputs.tf b/outputs.tf
index 1e87e6b..721df90 100644
--- a/outputs.tf
+++ b/outputs.tf
@@ -16,42 +16,50 @@
 
 output "email" {
   description = "Service account email (single-use case)."
-  value       = "${element(google_service_account.service_accounts.*.email, 0)}"
+  value       = google_service_account.service_accounts[0].email
 }
 
 output "iam_email" {
   description = "IAM-format service account email (single-use case)."
-  value       = "serviceAccount:${element(google_service_account.service_accounts.*.email, 0)}"
+  value       = "serviceAccount:${google_service_account.service_accounts[0].email}"
 }
 
 output "emails" {
   description = "Map of service account emails."
-  value       = "${zipmap(var.names, google_service_account.service_accounts.*.email)}"
+  value       = zipmap(var.names, google_service_account.service_accounts.*.email)
 }
 
 output "iam_emails" {
   description = "IAM-format service account emails."
-  value       = "${zipmap(var.names, formatlist("serviceAccount:%s", google_service_account.service_accounts.*.email))}"
+  value = zipmap(
+    var.names,
+    formatlist(
+      "serviceAccount:%s",
+      google_service_account.service_accounts.*.email,
+    ),
+  )
 }
 
 data "template_file" "keys" {
-  count    = "${length(var.names)}"
+  count    = length(var.names)
   template = "$${key}"
 
-  vars {
-    key = "${
-      var.generate_keys
-      ? base64decode(element(
-        concat(google_service_account_key.keys.*.private_key, list("")),
-        count.index
-      ))
-      : ""
-    }"
+  vars = {
+    key = var.generate_keys ? base64decode(
+      element(
+        concat(google_service_account_key.keys.*.private_key, [""]),
+        count.index,
+      ),
+    ) : ""
   }
 }
 
 output "keys" {
   description = "Map of service account keys."
   sensitive   = true
-  value       = "${zipmap(formatlist("%s-key.json", var.names), data.template_file.keys.*.rendered)}"
+  value = zipmap(
+    formatlist("%s-key.json", var.names),
+    data.template_file.keys.*.rendered,
+  )
 }
+
diff --git a/test/fixtures/multiple_service_accounts/main.tf b/test/fixtures/multiple_service_accounts/main.tf
index 7a2c9ef..c20a3e1 100644
--- a/test/fixtures/multiple_service_accounts/main.tf
+++ b/test/fixtures/multiple_service_accounts/main.tf
@@ -16,5 +16,6 @@
 
 module "example" {
   source     = "../../../examples/multiple_service_accounts"
-  project_id = "${var.project_id}"
+  project_id = var.project_id
 }
+
diff --git a/test/fixtures/multiple_service_accounts/outputs.tf b/test/fixtures/multiple_service_accounts/outputs.tf
index 85a01d5..587e1e2 100644
--- a/test/fixtures/multiple_service_accounts/outputs.tf
+++ b/test/fixtures/multiple_service_accounts/outputs.tf
@@ -16,10 +16,11 @@
 
 output "emails" {
   description = "The service account emails."
-  value       = "${module.example.emails}"
+  value       = module.example.emails
 }
 
 output "project_id" {
   description = "Project id variable."
-  value       = "${var.project_id}"
+  value       = var.project_id
 }
+
diff --git a/test/fixtures/multiple_service_accounts/variables.tf b/test/fixtures/multiple_service_accounts/variables.tf
index 093f6b1..1f95eaa 100644
--- a/test/fixtures/multiple_service_accounts/variables.tf
+++ b/test/fixtures/multiple_service_accounts/variables.tf
@@ -16,5 +16,6 @@
 
 variable "project_id" {
   description = "The ID of the project in which to provision resources."
-  type        = "string"
+  type        = string
 }
+
diff --git a/test/fixtures/multiple_service_accounts/versions.tf b/test/fixtures/multiple_service_accounts/versions.tf
new file mode 100644
index 0000000..2970427
--- /dev/null
+++ b/test/fixtures/multiple_service_accounts/versions.tf
@@ -0,0 +1,19 @@
+/**
+ * Copyright 2019 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+terraform {
+  required_version = ">= 0.12"
+}
diff --git a/test/fixtures/single_service_account/main.tf b/test/fixtures/single_service_account/main.tf
index d3a0f7a..74ec8f5 100644
--- a/test/fixtures/single_service_account/main.tf
+++ b/test/fixtures/single_service_account/main.tf
@@ -16,5 +16,6 @@
 
 module "example" {
   source     = "../../../examples/single_service_account"
-  project_id = "${var.project_id}"
+  project_id = var.project_id
 }
+
diff --git a/test/fixtures/single_service_account/outputs.tf b/test/fixtures/single_service_account/outputs.tf
index f11f73d..ab01cda 100644
--- a/test/fixtures/single_service_account/outputs.tf
+++ b/test/fixtures/single_service_account/outputs.tf
@@ -16,15 +16,16 @@
 
 output "email" {
   description = "The service account email."
-  value       = "${module.example.email}"
+  value       = module.example.email
 }
 
 output "iam_email" {
   description = "The service account IAM-format email."
-  value       = "${module.example.iam_email}"
+  value       = module.example.iam_email
 }
 
 output "project_id" {
   description = "Project id variable."
-  value       = "${var.project_id}"
+  value       = var.project_id
 }
+
diff --git a/test/fixtures/single_service_account/variables.tf b/test/fixtures/single_service_account/variables.tf
index 093f6b1..1f95eaa 100644
--- a/test/fixtures/single_service_account/variables.tf
+++ b/test/fixtures/single_service_account/variables.tf
@@ -16,5 +16,6 @@
 
 variable "project_id" {
   description = "The ID of the project in which to provision resources."
-  type        = "string"
+  type        = string
 }
+
diff --git a/test/fixtures/single_service_account/versions.tf b/test/fixtures/single_service_account/versions.tf
new file mode 100644
index 0000000..832ec1d
--- /dev/null
+++ b/test/fixtures/single_service_account/versions.tf
@@ -0,0 +1,19 @@
+/**
+ * Copyright 2018 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+terraform {
+  required_version = ">= 0.12"
+}
diff --git a/test/integration/multiple_service_accounts/controls/gcp.rb b/test/integration/multiple_service_accounts/controls/gcp.rb
index a8b91b4..a6c671f 100644
--- a/test/integration/multiple_service_accounts/controls/gcp.rb
+++ b/test/integration/multiple_service_accounts/controls/gcp.rb
@@ -4,7 +4,7 @@
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
-#      http://www.apache.org/licenses/LICENSE-2.0
+#     https://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
diff --git a/test/integration/single_service_account/controls/gcp.rb b/test/integration/single_service_account/controls/gcp.rb
index c382ce7..bd731bb 100644
--- a/test/integration/single_service_account/controls/gcp.rb
+++ b/test/integration/single_service_account/controls/gcp.rb
@@ -4,7 +4,7 @@
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
-#      http://www.apache.org/licenses/LICENSE-2.0
+#     https://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
diff --git a/test/make.sh b/test/make.sh
index a5b3aeb..803acd7 100755
--- a/test/make.sh
+++ b/test/make.sh
@@ -62,28 +62,14 @@ function basefiles() {
   done
 }
 
-# This function runs the hadolint linter on
-# every file named 'Dockerfile'
-function docker() {
-  echo "Running hadolint on Dockerfiles"
-  find_files . -name "Dockerfile" -print0 \
-    | compat_xargs -0 hadolint
-}
-
 # This function runs 'terraform validate' and 'terraform fmt'
 # against all directory paths which contain *.tf files.
 function check_terraform() {
-  set -e
   echo "Running terraform validate"
-  find_files . -name "*.tf" -print0 \
-    | compat_xargs -0 -n1 dirname \
-    | sort -u \
-    | compat_xargs -t -n1 terraform validate --check-variables=false
+  #shellcheck disable=SC2156
+  find . -name "*.tf" -not -path "./test/fixtures/shared/*" -not -path "./test/fixtures/all_examples/*" -exec bash -c 'cd $(dirname "{}") && terraform init && terraform validate ' \;
   echo "Running terraform fmt"
-  find_files . -name "*.tf" -print0 \
-    | compat_xargs -0 -n1 dirname \
-    | sort -u \
-    | compat_xargs -t -n1 terraform fmt -check=true -write=false
+  find_files . -name "*.tf" -exec terraform fmt  -check=true -write=false {} \;
 }
 
 # This function runs 'go fmt' and 'go vet' on every file
diff --git a/variables.tf b/variables.tf
index 357e57b..1fe774f 100644
--- a/variables.tf
+++ b/variables.tf
@@ -15,45 +15,55 @@
  */
 
 variable "project_id" {
+  type        = string
   description = "Project id where service account will be created."
 }
 
 variable "prefix" {
+  type        = string
   description = "Prefix applied to service account names."
   default     = ""
 }
 
 variable "names" {
+  type        = list(string)
   description = "Names of the service accounts to create."
   default     = []
 }
 
 variable "project_roles" {
+  type        = list(string)
   description = "Common roles to apply to all service accounts, project=>role as elements."
   default     = []
 }
 
 variable "grant_billing_role" {
+  type        = bool
   description = "Grant billing user role."
   default     = false
 }
 
 variable "billing_account_id" {
+  type        = string
   description = "If assigning billing role, specificy a billing account (default is to assign at the organizational level)."
   default     = ""
 }
 
 variable "grant_xpn_roles" {
+  type        = bool
   description = "Grant roles for shared VPC management."
   default     = true
 }
 
 variable "org_id" {
+  type        = string
   description = "Id of the organization for org-level roles."
   default     = ""
 }
 
 variable "generate_keys" {
+  type        = bool
   description = "Generate keys for service accounts."
   default     = false
 }
+
diff --git a/versions.tf b/versions.tf
new file mode 100644
index 0000000..2970427
--- /dev/null
+++ b/versions.tf
@@ -0,0 +1,19 @@
+/**
+ * Copyright 2019 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+terraform {
+  required_version = ">= 0.12"
+}