diff --git a/modules/eks-monitoring/alerts.tf b/modules/eks-monitoring/alerts.tf
index 1cae59b6..03740bdb 100644
--- a/modules/eks-monitoring/alerts.tf
+++ b/modules/eks-monitoring/alerts.tf
@@ -6,7 +6,7 @@ resource "aws_prometheus_rule_group_namespace" "alerting_rules" {
   count = var.enable_alerting_rules ? 1 : 0
 
   name         = "accelerator-infra-alerting"
-  workspace_id = var.managed_prometheus_workspace_id
+  workspace_id = local.managed_prometheus_workspace_id
   data         = <<EOF
 groups:
   - name: infra-alerts-01
diff --git a/modules/eks-monitoring/rules.tf b/modules/eks-monitoring/rules.tf
index 6969aafa..1f4e3250 100644
--- a/modules/eks-monitoring/rules.tf
+++ b/modules/eks-monitoring/rules.tf
@@ -7,7 +7,7 @@
 resource "aws_prometheus_rule_group_namespace" "recording_rules" {
   count        = var.enable_recording_rules ? 1 : 0
   name         = "accelerator-infra-rules"
-  workspace_id = var.managed_prometheus_workspace_id
+  workspace_id = local.managed_prometheus_workspace_id
   data         = <<EOF
 groups:
   - name: infra-rules-01