diff --git a/x-pack/plugins/fleet/server/services/epm/elasticsearch/template/template.test.ts b/x-pack/plugins/fleet/server/services/epm/elasticsearch/template/template.test.ts
index c06d0cdbb6429..dbc93e35c8218 100644
--- a/x-pack/plugins/fleet/server/services/epm/elasticsearch/template/template.test.ts
+++ b/x-pack/plugins/fleet/server/services/epm/elasticsearch/template/template.test.ts
@@ -1900,9 +1900,19 @@ describe('EPM template', () => {
 
     it('should fill constant keywords from previous mappings', async () => {
       const esClient = elasticsearchServiceMock.createElasticsearchClient();
+
       esClient.indices.getDataStream.mockResponse({
-        data_streams: [{ name: 'test-constant.keyword-default' }],
+        data_streams: [
+          {
+            name: 'test-constant.keyword-default',
+            indices: [
+              { index_name: '.ds-test-constant.keyword-default-0001' },
+              { index_name: '.ds-test-constant.keyword-default-0002' },
+            ],
+          },
+        ],
       } as any);
+
       esClient.indices.get.mockResponse({
         'test-constant.keyword-default': {
           mappings: {
@@ -1942,6 +1952,9 @@ describe('EPM template', () => {
           } as any,
         },
       ]);
+      expect(esClient.indices.get).toBeCalledWith({
+        index: '.ds-test-constant.keyword-default-0002',
+      });
       const putMappingsCalls = esClient.indices.putMapping.mock.calls;
       expect(putMappingsCalls).toHaveLength(1);
       expect(putMappingsCalls[0][0]).toEqual({
diff --git a/x-pack/plugins/fleet/server/services/epm/elasticsearch/template/template.ts b/x-pack/plugins/fleet/server/services/epm/elasticsearch/template/template.ts
index b9c0846f3e4f2..bb38480fd66b7 100644
--- a/x-pack/plugins/fleet/server/services/epm/elasticsearch/template/template.ts
+++ b/x-pack/plugins/fleet/server/services/epm/elasticsearch/template/template.ts
@@ -65,6 +65,7 @@ export interface CurrentDataStream {
   dataStreamName: string;
   replicated: boolean;
   indexTemplate: IndexTemplate;
+  currentWriteIndex: string;
 }
 
 const DEFAULT_IGNORE_ABOVE = 1024;
@@ -954,6 +955,7 @@ const getDataStreams = async (
     dataStreamName: dataStream.name,
     replicated: dataStream.replicated,
     indexTemplate,
+    currentWriteIndex: dataStream.indices?.at(-1)?.index_name,
   }));
 };
 
@@ -989,6 +991,7 @@ const updateAllDataStreams = async (
       return updateExistingDataStream({
         esClient,
         logger,
+        currentWriteIndex: templateEntry.currentWriteIndex,
         dataStreamName: templateEntry.dataStreamName,
         options,
       });
@@ -1002,11 +1005,13 @@ const updateAllDataStreams = async (
 
 const updateExistingDataStream = async ({
   dataStreamName,
+  currentWriteIndex,
   esClient,
   logger,
   options,
 }: {
   dataStreamName: string;
+  currentWriteIndex: string;
   esClient: ElasticsearchClient;
   logger: Logger;
   options?: {
@@ -1015,7 +1020,7 @@ const updateExistingDataStream = async ({
   };
 }) => {
   const existingDs = await esClient.indices.get({
-    index: dataStreamName,
+    index: currentWriteIndex,
   });
 
   const existingDsConfig = Object.values(existingDs);