diff --git a/modules/secure-serverless-harness/main.tf b/modules/secure-serverless-harness/main.tf
index a811844e2..0270c5200 100644
--- a/modules/secure-serverless-harness/main.tf
+++ b/modules/secure-serverless-harness/main.tf
@@ -54,12 +54,13 @@ module "network_project" {
   version = "~> 18.0"
   count   = var.use_shared_vpc ? 1 : 0
 
-  random_project_id = "true"
-  activate_apis     = local.network_apis
-  name              = var.network_project_name
-  org_id            = var.org_id
-  billing_account   = var.billing_account
-  folder_id         = google_folder.fld_serverless.name
+  random_project_id        = "true"
+  random_project_id_length = 4
+  activate_apis            = local.network_apis
+  name                     = var.network_project_name
+  org_id                   = var.org_id
+  billing_account          = var.billing_account
+  folder_id                = google_folder.fld_serverless.name
 
   disable_services_on_destroy = var.disable_services_on_destroy
   deletion_policy             = var.project_deletion_policy
@@ -71,12 +72,13 @@ module "security_project" {
   source  = "terraform-google-modules/project-factory/google"
   version = "~> 18.0"
 
-  random_project_id = "true"
-  activate_apis     = local.kms_apis
-  name              = var.security_project_name
-  org_id            = var.org_id
-  billing_account   = var.billing_account
-  folder_id         = google_folder.fld_serverless.name
+  random_project_id        = "true"
+  random_project_id_length = 4
+  activate_apis            = local.kms_apis
+  name                     = var.security_project_name
+  org_id                   = var.org_id
+  billing_account          = var.billing_account
+  folder_id                = google_folder.fld_serverless.name
 
   disable_services_on_destroy = var.disable_services_on_destroy
   deletion_policy             = var.project_deletion_policy
diff --git a/modules/service-project-factory/main.tf b/modules/service-project-factory/main.tf
index bc79c33aa..5b181a0db 100644
--- a/modules/service-project-factory/main.tf
+++ b/modules/service-project-factory/main.tf
@@ -19,6 +19,7 @@ module "serverless_project" {
   version = "~> 18.0"
 
   random_project_id           = "true"
+  random_project_id_length    = 4
   activate_apis               = var.activate_apis
   name                        = var.project_name
   org_id                      = var.org_id
diff --git a/test/fixtures/secure_cloud_run/harness.tf b/test/fixtures/secure_cloud_run/harness.tf
index 084c7fa04..896a1626f 100644
--- a/test/fixtures/secure_cloud_run/harness.tf
+++ b/test/fixtures/secure_cloud_run/harness.tf
@@ -49,12 +49,13 @@ module "serverless_project" {
   source  = "terraform-google-modules/project-factory/google"
   version = "~> 18.0"
 
-  name              = "ci-cloud-run"
-  random_project_id = "true"
-  org_id            = var.org_id
-  folder_id         = local.folder_id
-  billing_account   = var.billing_account
-  deletion_policy   = "DELETE"
+  name                     = "ci-cloud-run"
+  random_project_id        = "true"
+  random_project_id_length = 4
+  org_id                   = var.org_id
+  folder_id                = local.folder_id
+  billing_account          = var.billing_account
+  deletion_policy          = "DELETE"
 
   svpc_host_project_id               = data.terraform_remote_state.sfb-network-prod.outputs.restricted_host_project_id
   vpc_service_control_attach_enabled = true
@@ -77,12 +78,13 @@ module "kms_project" {
   source  = "terraform-google-modules/project-factory/google"
   version = "~> 18.0"
 
-  name              = "ci-cloud-run-kms"
-  random_project_id = "true"
-  org_id            = var.org_id
-  folder_id         = local.folder_id
-  billing_account   = var.billing_account
-  deletion_policy   = "DELETE"
+  name                     = "ci-cloud-run-kms"
+  random_project_id        = "true"
+  random_project_id_length = 4
+  org_id                   = var.org_id
+  folder_id                = local.folder_id
+  billing_account          = var.billing_account
+  deletion_policy          = "DELETE"
 
   svpc_host_project_id               = data.terraform_remote_state.sfb-network-prod.outputs.restricted_host_project_id
   vpc_service_control_attach_enabled = true
diff --git a/test/setup/main.tf b/test/setup/main.tf
index 1a20e1cc1..b1e7dd95f 100644
--- a/test/setup/main.tf
+++ b/test/setup/main.tf
@@ -137,13 +137,14 @@ module "project" {
   source  = "terraform-google-modules/project-factory/google"
   version = "~> 18.0"
 
-  name                    = "ci-cloud-run"
-  random_project_id       = "true"
-  org_id                  = var.org_id
-  folder_id               = var.folder_id
-  billing_account         = var.billing_account
-  default_service_account = "keep"
-  deletion_policy         = "DELETE"
+  name                     = "ci-cloud-run"
+  random_project_id        = "true"
+  random_project_id_length = 4
+  org_id                   = var.org_id
+  folder_id                = var.folder_id
+  billing_account          = var.billing_account
+  default_service_account  = "keep"
+  deletion_policy          = "DELETE"
 
   activate_apis = flatten(values(local.per_module_services))
 }