diff --git a/environments/.stackhpc/tofu/cluster_image.auto.tfvars.json b/environments/.stackhpc/tofu/cluster_image.auto.tfvars.json
index f9e568c3f..0afb56887 100644
--- a/environments/.stackhpc/tofu/cluster_image.auto.tfvars.json
+++ b/environments/.stackhpc/tofu/cluster_image.auto.tfvars.json
@@ -1,6 +1,10 @@
 {
-    "cluster_image": {
-        "RL8": "openhpc-RL8-250102-1138-77cfc703",
-        "RL9": "openhpc-RL9-250102-1139-77cfc703"
+    "cluster_image_names": {
+        "RL8": {
+            "default": "openhpc-RL8-250102-1138-77cfc703"
+        },
+        "RL9": {
+            "default": "openhpc-RL9-250102-1139-77cfc703"
+        }
     }
 }
diff --git a/environments/.stackhpc/tofu/main.tf b/environments/.stackhpc/tofu/main.tf
index ac57f503a..31cdb8157 100644
--- a/environments/.stackhpc/tofu/main.tf
+++ b/environments/.stackhpc/tofu/main.tf
@@ -1,3 +1,4 @@
+
 # This terraform configuration uses the "skeleton" terraform, so that is checked by CI.
 
 terraform {
@@ -25,9 +26,9 @@ variable "os_version" {
   default = "RL9"
 }
 
-variable "cluster_image" {
-    description = "single image for all cluster nodes, keyed by os_version - a convenience for CI"
-    type = map(string)
+variable "cluster_image_names" {
+    description = "image *names* keyed by os_version, for CI"
+    type = map(map(string))
 }
 
 variable "cluster_net" {}
@@ -58,8 +59,10 @@ variable "k3s_token" {
     type = string
 }
 
-data "openstack_images_image_v2" "cluster" {
-    name = var.cluster_image[var.os_version]
+data "openstack_images_image_v2" "cluster_images" {
+    for_each = var.cluster_image_names[var.os_version]
+
+    name = each.value
     most_recent = true
 }
 
@@ -71,7 +74,7 @@ module "cluster" {
     cluster_subnet = var.cluster_subnet
     vnic_type = var.vnic_type
     key_pair = "slurm-app-ci"
-    cluster_image_id = data.openstack_images_image_v2.cluster.id
+    cluster_image_ids = {for key, img in data.openstack_images_image_v2.cluster_images: key => img.id}
     control_node_flavor = var.control_node_flavor
     k3s_token = var.k3s_token
 
diff --git a/environments/skeleton/{{cookiecutter.environment}}/tofu/compute.tf b/environments/skeleton/{{cookiecutter.environment}}/tofu/compute.tf
index 14c728a5a..9dc0e05c7 100644
--- a/environments/skeleton/{{cookiecutter.environment}}/tofu/compute.tf
+++ b/environments/skeleton/{{cookiecutter.environment}}/tofu/compute.tf
@@ -10,7 +10,7 @@ module "compute" {
   cluster_subnet_id = data.openstack_networking_subnet_v2.cluster_subnet.id
 
   flavor = each.value.flavor
-  image_id = lookup(each.value, "image_id", var.cluster_image_id)
+  image_id = lookup(var.cluster_image_ids, each.key, var.cluster_image_ids["default"])
   vnic_type = lookup(each.value, "vnic_type", var.vnic_type)
   vnic_profile = lookup(each.value, "vnic_profile", var.vnic_profile)
   key_pair = var.key_pair
diff --git a/environments/skeleton/{{cookiecutter.environment}}/tofu/nodes.tf b/environments/skeleton/{{cookiecutter.environment}}/tofu/nodes.tf
index 8ea8cabcb..bf5900324 100644
--- a/environments/skeleton/{{cookiecutter.environment}}/tofu/nodes.tf
+++ b/environments/skeleton/{{cookiecutter.environment}}/tofu/nodes.tf
@@ -45,13 +45,13 @@ resource "openstack_compute_instance_v2" "control" {
   for_each = toset(["control"])
   
   name = "${var.cluster_name}-${each.key}"
-  image_id = var.cluster_image_id
+  image_id = var.cluster_image_ids["default"]
   flavor_name = var.control_node_flavor
   key_pair = var.key_pair
   
   # root device:
   block_device {
-      uuid = var.cluster_image_id
+      uuid = var.cluster_image_ids["default"]
       source_type  = "image"
       destination_type = var.volume_backed_instances ? "volume" : "local"
       volume_size = var.volume_backed_instances ? var.root_volume_size : null
@@ -102,14 +102,14 @@ resource "openstack_compute_instance_v2" "login" {
   for_each = var.login_nodes
   
   name = "${var.cluster_name}-${each.key}"
-  image_id = var.cluster_image_id
+  image_id = var.cluster_image_ids["default"]
   flavor_name = each.value
   key_pair = var.key_pair
 
   dynamic "block_device" {
     for_each = var.volume_backed_instances ? [1]: []
     content {
-      uuid = var.cluster_image_id
+      uuid = var.cluster_image_ids["default"]
       source_type  = "image"
       destination_type = "volume"
       volume_size = var.root_volume_size
diff --git a/environments/skeleton/{{cookiecutter.environment}}/tofu/variables.tf b/environments/skeleton/{{cookiecutter.environment}}/tofu/variables.tf
index 0f5eefa18..2e71e0c5c 100644
--- a/environments/skeleton/{{cookiecutter.environment}}/tofu/variables.tf
+++ b/environments/skeleton/{{cookiecutter.environment}}/tofu/variables.tf
@@ -34,9 +34,13 @@ variable "login_nodes" {
   description = "Mapping defining login nodes: key -> (str) nodename suffix, value -> (str) flavor name"
 }
 
-variable "cluster_image_id" {
-    type = string
-    description = "ID of default image for the cluster"
+variable "cluster_image_ids" {
+    type = map(string)
+    description = <<-EOF
+     Mapping of UUIDs defining images for the cluster. Valid keys are:
+        - "default": required, defines default image for cluster
+        - any key from "compute" variable, to define different images for compute node groups
+    EOF
 }
 
 variable "compute" {
@@ -49,7 +53,6 @@ variable "compute" {
             nodes: List of node names
             flavor: String flavor name
         Optional:
-            image_id: Overrides variable cluster_image_id
             vnic_type: Overrides variable vnic_type
             vnic_profile: Overrides variable vnic_profile
     EOF