diff --git a/x-pack/plugins/alerting/server/authorization/alerting_authorization.ts b/x-pack/plugins/alerting/server/authorization/alerting_authorization.ts
index de49cdd370585..655e1f7ce095c 100644
--- a/x-pack/plugins/alerting/server/authorization/alerting_authorization.ts
+++ b/x-pack/plugins/alerting/server/authorization/alerting_authorization.ts
@@ -143,7 +143,7 @@ export class AlertingAuthorization {
    * used by the RAC/Alerts client
    */
   public async getAugmentRuleTypesWithAuthorization(
-    featureIds: string[],
+    featureIds: readonly string[],
     operations: Array<ReadOperations | WriteOperations>,
     authorizationEntity: AlertingAuthorizationEntity
   ): Promise<{
diff --git a/x-pack/plugins/rule_registry/server/alert_data_client/alerts_client.ts b/x-pack/plugins/rule_registry/server/alert_data_client/alerts_client.ts
index 81d43b0013767..197ee95fab4ae 100644
--- a/x-pack/plugins/rule_registry/server/alert_data_client/alerts_client.ts
+++ b/x-pack/plugins/rule_registry/server/alert_data_client/alerts_client.ts
@@ -46,9 +46,12 @@ interface GetAlertParams {
   index?: string;
 }
 
-export const mapConsumerToIndexName = {
-  observability: '.alerts-observability',
+export const validFeatureIds = ['apm', 'observability', 'siem'] as const;
+export type ValidFeatureIds = typeof validFeatureIds[number];
+
+export const mapConsumerToIndexName: { [featureId in ValidFeatureIds]: string | string[] } = {
   apm: '.alerts-observability-apm',
+  observability: '.alerts-observability',
   siem: ['.alerts-security-solution', '.siem-signals'],
 };
 
@@ -75,7 +78,7 @@ export class AlertsClient {
     operations: Array<ReadOperations | WriteOperations>
   ) {
     return this.authorization.getAugmentRuleTypesWithAuthorization(
-      featureIds.length !== 0 ? featureIds : Object.keys(mapConsumerToIndexName),
+      featureIds.length !== 0 ? featureIds : validFeatureIds,
       operations,
       AlertingAuthorizationEntity.Alert
     );
@@ -203,10 +206,10 @@ export class AlertsClient {
   }
 
   public async getAuthorizedAlertsIndices(
-    featureIds: Array<keyof typeof mapConsumerToIndexName>
+    featureIds: readonly ValidFeatureIds[]
   ): Promise<string[] | undefined> {
     const augmentedRuleTypes = await this.authorization.getAugmentRuleTypesWithAuthorization(
-      featureIds,
+      featureIds as string[],
       [ReadOperations.Find, ReadOperations.Get, WriteOperations.Update],
       AlertingAuthorizationEntity.Alert
     );
@@ -219,11 +222,14 @@ export class AlertsClient {
       authorizedFeatures.add(ruleType.producer);
     }
 
-    const typeguard = (a: string): a is keyof typeof mapConsumerToIndexName =>
-      a in Object.keys(mapConsumerToIndexName);
+    const isValidFeatureId = (a: string): a is ValidFeatureIds =>
+      // @ts-expect-error Argument of type 'string' is not assignable to parameter of type '"apm" | "observability" | "siem"'
+      validFeatureIds.includes(a);
 
     const toReturn = Array.from(authorizedFeatures).flatMap((feature) => {
-      if (typeguard(feature)) return mapConsumerToIndexName[feature];
+      if (isValidFeatureId(feature)) {
+        return mapConsumerToIndexName[feature];
+      }
       return [];
     });
 
diff --git a/x-pack/plugins/rule_registry/server/routes/get_alert_index.ts b/x-pack/plugins/rule_registry/server/routes/get_alert_index.ts
index bfafec919ebb2..a394fc7262570 100644
--- a/x-pack/plugins/rule_registry/server/routes/get_alert_index.ts
+++ b/x-pack/plugins/rule_registry/server/routes/get_alert_index.ts
@@ -11,6 +11,7 @@ import { transformError } from '@kbn/securitysolution-es-utils';
 
 import { RacRequestHandlerContext } from '../types';
 import { BASE_RAC_ALERTS_API_PATH } from '../../common/constants';
+import { validFeatureIds } from '../alert_data_client/alerts_client';
 
 export const getAlertsIndexRoute = (router: IRouter<RacRequestHandlerContext>) => {
   router.get(
@@ -22,14 +23,9 @@ export const getAlertsIndexRoute = (router: IRouter<RacRequestHandlerContext>) =
       },
     },
     async (context, request, response) => {
-      const APM_SERVER_FEATURE_ID = 'apm';
-      const SERVER_APP_ID = 'siem';
       try {
         const alertsClient = await context.rac.getAlertsClient();
-        const indexName = await alertsClient.getAuthorizedAlertsIndices([
-          APM_SERVER_FEATURE_ID,
-          SERVER_APP_ID,
-        ]);
+        const indexName = await alertsClient.getAuthorizedAlertsIndices(validFeatureIds);
         return response.ok({
           body: { index_name: indexName },
         });
diff --git a/x-pack/plugins/rule_registry/server/rule_data_client/types.ts b/x-pack/plugins/rule_registry/server/rule_data_client/types.ts
index 5e168df32521f..458f3ccbef9bb 100644
--- a/x-pack/plugins/rule_registry/server/rule_data_client/types.ts
+++ b/x-pack/plugins/rule_registry/server/rule_data_client/types.ts
@@ -11,7 +11,7 @@ import { ElasticsearchClient } from 'kibana/server';
 import { FieldDescriptor } from 'src/plugins/data/server';
 import { ESSearchRequest, ESSearchResponse } from 'src/core/types/elasticsearch';
 import { TechnicalRuleDataFieldName } from '../../common/technical_rule_data_field_names';
-import { mapConsumerToIndexName } from '../alert_data_client/alerts_client';
+import { ValidFeatureIds } from '../alert_data_client/alerts_client';
 
 export interface RuleDataReader {
   search<TSearchRequest extends ESSearchRequest>(
@@ -38,8 +38,6 @@ export interface IRuleDataClient {
   createOrUpdateWriteTarget(options: { namespace?: string }): Promise<void>;
 }
 
-type ValidFeatureIds = keyof typeof mapConsumerToIndexName;
-
 export interface RuleDataClientConstructorOptions {
   getClusterClient: () => Promise<ElasticsearchClient>;
   ready: () => Promise<void>;