diff --git a/docs/proposals/20220411-cluster-api-state-metrics.md b/docs/proposals/20220411-cluster-api-state-metrics.md
index 72853fa34788..e1259dd7fef9 100644
--- a/docs/proposals/20220411-cluster-api-state-metrics.md
+++ b/docs/proposals/20220411-cluster-api-state-metrics.md
@@ -283,6 +283,7 @@ Common labels:
 | `capi_machineset_labels`                        | `1`                               | Gauge | `.metadata.labels`                                  | common       |
 | `capi_machineset_created`                       | `.metadata.creationTimestamp`     | Gauge |                                                     | common       |
 | `capi_machineset_paused`                        | `annotations.HasPaused()`         | Gauge |                                                     |              |
+| `capi_machineset_status_available_replicas`     | `.status.availableReplicas`       | Gauge |                                                     | [ReplicaSet] |
 | `capi_machineset_status_condition`              | `.status.conditions==<condition>` | Gauge | `condition=<condition>` `status=<true\|false>`      |              |
 | `capi_machineset_status_replicas`               | `.status.replicas`                | Gauge |                                                     | [ReplicaSet] |
 | `capi_machineset_status_fully_labeled_replicas` | `.status.fullyLabeledReplicas`    | Gauge |                                                     | [ReplicaSet] |