diff --git a/ci-operator/step-registry/sandboxed-containers-operator/peerpods/param-cm/sandboxed-containers-operator-peerpods-param-cm-commands.sh b/ci-operator/step-registry/sandboxed-containers-operator/peerpods/param-cm/sandboxed-containers-operator-peerpods-param-cm-commands.sh
index 5efbe820f55cf..5e2400096049c 100755
--- a/ci-operator/step-registry/sandboxed-containers-operator/peerpods/param-cm/sandboxed-containers-operator-peerpods-param-cm-commands.sh
+++ b/ci-operator/step-registry/sandboxed-containers-operator/peerpods/param-cm/sandboxed-containers-operator-peerpods-param-cm-commands.sh
@@ -69,7 +69,7 @@ EOF
       AWS_SG_IDS: "${AWS_SG_IDS}"
       VXLAN_PORT: "9000"
       PODVM_INSTANCE_TYPE: "t3.medium"
-      PODVM_INSTANCE_TYPES: "t3.small,t3.medium,t3.large,t3.xlarge,g4dn.2xlarge,g5.2xlarge,p3.2xlarge"
+      PODVM_INSTANCE_TYPES: "${PODVM_INSTANCE_TYPES}"
       PROXY_TIMEOUT: "30m"
 EOF
 }
diff --git a/ci-operator/step-registry/sandboxed-containers-operator/peerpods/param-cm/sandboxed-containers-operator-peerpods-param-cm-ref.yaml b/ci-operator/step-registry/sandboxed-containers-operator/peerpods/param-cm/sandboxed-containers-operator-peerpods-param-cm-ref.yaml
index 1d4d44b5bc950..261f745a1fc44 100644
--- a/ci-operator/step-registry/sandboxed-containers-operator/peerpods/param-cm/sandboxed-containers-operator-peerpods-param-cm-ref.yaml
+++ b/ci-operator/step-registry/sandboxed-containers-operator/peerpods/param-cm/sandboxed-containers-operator-peerpods-param-cm-ref.yaml
@@ -15,3 +15,10 @@ ref:
       operator with peer-pods enabled (networking setup, firewall rules,
       secrets, ...) and generates "peerpods-param-cm.yaml" to be
       consumed by openshift-tests-private [sig-kata] tests.
+  - name: PODVM_INSTANCE_TYPES
+    default: "t3.small,t3.medium,t3.large,t3.xlarge,g4dn.2xlarge,g5.2xlarge"
+    documentation: |-
+      Comma-separated list of AWS instance types to populate
+      PODVM_INSTANCE_TYPES in peerpods-param-cm. CAA validates all
+      entries at startup so only include types available in the target
+      region.