diff --git a/Terraform/main.tf b/Terraform/main.tf
index d5717d5..209fd01 100644
--- a/Terraform/main.tf
+++ b/Terraform/main.tf
@@ -33,7 +33,7 @@ resource "aws_subnet" "default" {
 # Adjust VPC DNS settings to not conflict with lab
 resource "aws_vpc_dhcp_options" "default" {
   domain_name          = "windomain.local"
-  domain_name_servers  = [aws_instance.dc.private_ip, var.external_dns_servers]
+  domain_name_servers  = concat(aws_instance.dc.private_ip, var.external_dns_servers)
   netbios_name_servers = [aws_instance.dc.private_ip]
 }