diff --git a/modules/gke-cluster/main.tf b/modules/gke-cluster/main.tf
index 9de06be8f..572e35c11 100644
--- a/modules/gke-cluster/main.tf
+++ b/modules/gke-cluster/main.tf
@@ -279,7 +279,7 @@ resource "google_container_cluster" "cluster" {
   }
 
   dynamic "notification_config" {
-    for_each = var.notification_config != null ? [""] : []
+    for_each = var.notification_config ? [""] : []
     content {
       pubsub {
         enabled = var.notification_config
diff --git a/modules/gke-cluster/outputs.tf b/modules/gke-cluster/outputs.tf
index 2ee357e6c..df0b40c18 100644
--- a/modules/gke-cluster/outputs.tf
+++ b/modules/gke-cluster/outputs.tf
@@ -48,5 +48,5 @@ output "name" {
 
 output "notifications" {
   description = "GKE PubSub notifications topic."
-  value       = google_pubsub_topic.notifications.id
+  value       = var.notification_config ? google_pubsub_topic.notifications[0].id : null
 }