diff --git a/ci/terraform/oidc/authdev1.tfvars b/ci/terraform/oidc/authdev1.tfvars
index f3149629b2..f6a54ced09 100644
--- a/ci/terraform/oidc/authdev1.tfvars
+++ b/ci/terraform/oidc/authdev1.tfvars
@@ -1,7 +1,7 @@
 shared_state_bucket = "di-auth-development-tfstate"
 
-# App-specific
-test_clients_enabled                        = "true"
+# Feature Flags
+test_clients_enabled                        = true
 ipv_api_enabled                             = true
 account_intervention_service_call_enabled   = true
 account_intervention_service_action_enabled = true
diff --git a/ci/terraform/oidc/authdev2.tfvars b/ci/terraform/oidc/authdev2.tfvars
index 85cab31fcf..861f66293c 100644
--- a/ci/terraform/oidc/authdev2.tfvars
+++ b/ci/terraform/oidc/authdev2.tfvars
@@ -1,7 +1,7 @@
 shared_state_bucket = "di-auth-development-tfstate"
 
 # App-specific
-test_clients_enabled                        = "true"
+test_clients_enabled                        = true
 ipv_api_enabled                             = true
 account_intervention_service_call_enabled   = true
 account_intervention_service_action_enabled = true
diff --git a/ci/terraform/oidc/mfa.tf b/ci/terraform/oidc/mfa.tf
index 3e24da15a1..5ca6ca305c 100644
--- a/ci/terraform/oidc/mfa.tf
+++ b/ci/terraform/oidc/mfa.tf
@@ -38,7 +38,7 @@ module "mfa" {
     EMAIL_QUEUE_URL                        = aws_sqs_queue.email_queue.id
     TXMA_AUDIT_QUEUE_URL                   = module.oidc_txma_audit.queue_url
     REDIS_KEY                              = local.redis_key
-    TEST_CLIENTS_ENABLED                   = var.test_clients_enabled
+    TEST_CLIENTS_ENABLED                   = var.test_clients_enabled ? "true" : "false"
     INTERNAl_SECTOR_URI                    = var.internal_sector_uri
     SUPPORT_REAUTH_SIGNOUT_ENABLED         = var.support_reauth_signout_enabled
   }
diff --git a/ci/terraform/oidc/sandpit.tfvars b/ci/terraform/oidc/sandpit.tfvars
index 5cab51577b..af88461412 100644
--- a/ci/terraform/oidc/sandpit.tfvars
+++ b/ci/terraform/oidc/sandpit.tfvars
@@ -1,7 +1,7 @@
 shared_state_bucket = "digital-identity-dev-tfstate"
 
 # App-specific
-test_clients_enabled                        = "true"
+test_clients_enabled                        = true
 ipv_api_enabled                             = true
 ipv_authorisation_callback_uri              = ""
 ipv_authorisation_uri                       = ""
diff --git a/ci/terraform/oidc/send_notification.tf b/ci/terraform/oidc/send_notification.tf
index 0a7fd13b49..4a28f584df 100644
--- a/ci/terraform/oidc/send_notification.tf
+++ b/ci/terraform/oidc/send_notification.tf
@@ -41,7 +41,7 @@ module "send_notification" {
     PENDING_EMAIL_CHECK_QUEUE_URL          = local.pending_email_check_queue_id
     TXMA_AUDIT_QUEUE_URL                   = module.oidc_txma_audit.queue_url
     REDIS_KEY                              = local.redis_key
-    TEST_CLIENTS_ENABLED                   = var.test_clients_enabled
+    TEST_CLIENTS_ENABLED                   = var.test_clients_enabled ? "true" : "false"
     DEFAULT_OTP_CODE_EXPIRY                = var.otp_code_ttl_duration
     EMAIL_OTP_ACCOUNT_CREATION_CODE_EXPIRY = var.email_acct_creation_otp_code_ttl_duration
     INTERNAl_SECTOR_URI                    = var.internal_sector_uri
diff --git a/ci/terraform/oidc/variables.tf b/ci/terraform/oidc/variables.tf
index 57d8914b22..3103f98594 100644
--- a/ci/terraform/oidc/variables.tf
+++ b/ci/terraform/oidc/variables.tf
@@ -254,8 +254,8 @@ variable "test_client_verify_phone_number_otp" {
 }
 
 variable "test_clients_enabled" {
-  type    = string
-  default = "false"
+  type    = bool
+  default = false
 }
 
 variable "client_registry_api_enabled" {
diff --git a/ci/terraform/oidc/verify_code.tf b/ci/terraform/oidc/verify_code.tf
index cf5d1e8cfe..52c8dab2ba 100644
--- a/ci/terraform/oidc/verify_code.tf
+++ b/ci/terraform/oidc/verify_code.tf
@@ -44,7 +44,7 @@ module "verify_code" {
     TERMS_CONDITIONS_VERSION                 = var.terms_and_conditions
     TEST_CLIENT_VERIFY_EMAIL_OTP             = var.test_client_verify_email_otp
     TEST_CLIENT_VERIFY_PHONE_NUMBER_OTP      = var.test_client_verify_phone_number_otp
-    TEST_CLIENTS_ENABLED                     = var.test_clients_enabled
+    TEST_CLIENTS_ENABLED                     = var.test_clients_enabled ? "true" : "false"
     INTERNAl_SECTOR_URI                      = var.internal_sector_uri
     CODE_MAX_RETRIES_INCREASED               = var.code_max_retries_increased
     REDUCED_LOCKOUT_DURATION                 = var.reduced_lockout_duration
diff --git a/ci/terraform/oidc/verify_mfa_code.tf b/ci/terraform/oidc/verify_mfa_code.tf
index f355caf5dd..a0d9354974 100644
--- a/ci/terraform/oidc/verify_mfa_code.tf
+++ b/ci/terraform/oidc/verify_mfa_code.tf
@@ -45,7 +45,7 @@ module "verify_mfa_code" {
     TERMS_CONDITIONS_VERSION                = var.terms_and_conditions
     TEST_CLIENT_VERIFY_EMAIL_OTP            = var.test_client_verify_email_otp
     TEST_CLIENT_VERIFY_PHONE_NUMBER_OTP     = var.test_client_verify_phone_number_otp
-    TEST_CLIENTS_ENABLED                    = var.test_clients_enabled
+    TEST_CLIENTS_ENABLED                    = var.test_clients_enabled ? "true" : "false"
     INTERNAl_SECTOR_URI                     = var.internal_sector_uri
     EXPERIAN_PHONE_CHECKER_QUEUE_URL        = local.experian_phone_check_sqs_queue_id
     PHONE_CHECKER_WITH_RETRY                = var.phone_checker_with_retry