diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e84813e..6c5381c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,11 +18,11 @@ jobs:
     strategy:
       matrix:
         terraform: [ 1.6.1 ]
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     container:
       image: hashicorp/terraform:${{ matrix.terraform }}
     steps:
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
       - run: terraform init -get -backend=false -input=false
       - run: terraform fmt -recursive -check=true -write=false
-      - run: terraform validate
+      - run: terraform validate --json
diff --git a/.github/workflows/pre_commit.yml b/.github/workflows/pre_commit.yml
index e837b70..1ead539 100644
--- a/.github/workflows/pre_commit.yml
+++ b/.github/workflows/pre_commit.yml
@@ -8,7 +8,7 @@ on: # yamllint disable-line rule:truthy
 
 jobs:
   pre_commit:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
       - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d # v5.1.0
diff --git a/main.tf b/main.tf
index 2ecdd8e..db1a573 100644
--- a/main.tf
+++ b/main.tf
@@ -4,7 +4,12 @@ data "aws_availability_zones" "available" {
 
 data "aws_security_group" "default" {
   name   = "default"
-  vpc_id = module.vpc.vpc_id
+  vpc_id = var.vpc_id == null ? module.vpc.vpc_id : var.vpc_id
+}
+
+locals {
+  vpc_id     = var.vpc_id == null ? module.vpc.vpc_id : var.vpc_id
+  create_vpc = local.vpc_id == module.vpc.vpc_id ? true : false
 }
 
 module "vpc" {
@@ -14,6 +19,8 @@ module "vpc" {
   name = "vpc-${var.environment}"
   cidr = "10.0.0.0/16"
 
+  create_vpc = local.create_vpc
+
   azs                     = [data.aws_availability_zones.available.names[0]]
   private_subnets         = ["10.0.1.0/24"]
   public_subnets          = ["10.0.101.0/24"]
@@ -33,7 +40,7 @@ module "vpc_endpoints" {
   source  = "terraform-aws-modules/vpc/aws//modules/vpc-endpoints"
   version = "5.8.1"
 
-  vpc_id = module.vpc.vpc_id
+  vpc_id = local.vpc_id
 
   endpoints = {
     s3 = {
@@ -60,7 +67,7 @@ module "runner-instance" {
   environment       = var.environment
   iam_object_prefix = random_id.unique_prefix.hex
 
-  vpc_id    = module.vpc.vpc_id
+  vpc_id    = local.vpc_id
   subnet_id = element(module.vpc.private_subnets, 0)
 
   runner_ami_filter                       = var.runner_ami_filter
@@ -145,8 +152,9 @@ module "runner-instance" {
   }
 
   runner_worker_docker_machine_instance = {
-    types     = var.runner_worker_docker_machine_instance_types
-    root_size = var.runner_worker_docker_machine_instance_root_size
+    types      = var.runner_worker_docker_machine_instance_types
+    root_size  = var.runner_worker_docker_machine_instance_root_size
+    subnet_ids = var.runner_worker_docker_machine_instance_subnet_ids
   }
 
   runner_networking = {
diff --git a/variables.tf b/variables.tf
index 4a9fde4..57ecf51 100644
--- a/variables.tf
+++ b/variables.tf
@@ -1,3 +1,13 @@
+variable "vpc_id" {
+  description = "The VPC used for the runner and runner workers."
+  type        = string
+}
+
+variable "runner_worker_docker_machine_instance_subnet_ids" {
+  description = "The VPC used for the runner and runner workers."
+  type        = list(string)
+}
+
 variable "aws_region" {
   description = "AWS region."
   type        = string