diff --git a/packages/kbn-es-archiver/src/lib/indices/kibana_index.ts b/packages/kbn-es-archiver/src/lib/indices/kibana_index.ts
index f234de43273014..91c0bd8343a360 100644
--- a/packages/kbn-es-archiver/src/lib/indices/kibana_index.ts
+++ b/packages/kbn-es-archiver/src/lib/indices/kibana_index.ts
@@ -77,7 +77,8 @@ export async function migrateKibanaIndex({
 async function fetchKibanaIndices(client: Client) {
   const kibanaIndices = await client.cat.indices({ index: '.kibana*', format: 'json' });
   const isKibanaIndex = (index: string) =>
-    /^\.kibana(:?_\d*)?$/.test(index) || /^\.kibana_(pre)*\d+\.\d+\.\d+/.test(index);
+    /^\.kibana(:?_\d*)?$/.test(index) ||
+    /^\.kibana(_task_manager)?_(pre)?\d+\.\d+\.\d+/.test(index);
   return kibanaIndices.map((x: { index: string }) => x.index).filter(isKibanaIndex);
 }
 
@@ -104,7 +105,7 @@ export async function cleanKibanaIndices({
 
   while (true) {
     const resp = await client.deleteByQuery({
-      index: `.kibana`,
+      index: `.kibana,.kibana_task_manager`,
       body: {
         query: {
           bool: {
@@ -116,7 +117,7 @@ export async function cleanKibanaIndices({
           },
         },
       },
-      ignore: [409],
+      ignore: [404, 409],
     });
 
     if (resp.total !== resp.deleted) {
diff --git a/x-pack/test/alerting_api_integration/security_and_spaces/tests/alerting/index.ts b/x-pack/test/alerting_api_integration/security_and_spaces/tests/alerting/index.ts
index 8ed979a1711694..2a256266697e62 100644
--- a/x-pack/test/alerting_api_integration/security_and_spaces/tests/alerting/index.ts
+++ b/x-pack/test/alerting_api_integration/security_and_spaces/tests/alerting/index.ts
@@ -11,10 +11,6 @@ import { setupSpacesAndUsers, tearDown } from '..';
 export default function alertingTests({ loadTestFile, getService }: FtrProviderContext) {
   describe('Alerts', () => {
     describe('legacy alerts', () => {
-      before(async () => {
-        await setupSpacesAndUsers(getService);
-      });
-
       after(async () => {
         await tearDown(getService);
       });