diff --git a/README.md b/README.md
index 7abeeb7..ea4f8b7 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@ Setup a basic ECS cluster with the needed IAM rights.
  * [`environment`]: String(required):  For what environment is this cluster needed (eg staging, production, ...)
 ### Output
  * [`cluster_name`]: String: The name of the ECS cluster.
+ * [`cluster_id`]: String: The ID (ARN) of the ECS cluster.
  * [`ecs-instance-profile`]: IAM instance profile that you need to give to your instances.
  * [`ecs-service-role`]: IAM service role for you ECS to manage your loadbalancers
 
diff --git a/ecs-cluster/outputs.tf b/ecs-cluster/outputs.tf
index bd6cf4e..adcbdc4 100644
--- a/ecs-cluster/outputs.tf
+++ b/ecs-cluster/outputs.tf
@@ -2,6 +2,10 @@ output "cluster_name" {
   value = "${aws_ecs_cluster.cluster.name}"
 }
 
+output "cluster_id" {
+  value = "${aws_ecs_cluster.cluster.id}"
+}
+
 output "ecs-instance-profile" {
   value = "${aws_iam_instance_profile.ecs-instance-profile.name}"
 }