diff --git a/modules/data-streams/src/main/java/org/elasticsearch/datastreams/action/TransportPromoteDataStreamAction.java b/modules/data-streams/src/main/java/org/elasticsearch/datastreams/action/TransportPromoteDataStreamAction.java
index ae0bfc49c5e70..6aa3f1d3e93da 100644
--- a/modules/data-streams/src/main/java/org/elasticsearch/datastreams/action/TransportPromoteDataStreamAction.java
+++ b/modules/data-streams/src/main/java/org/elasticsearch/datastreams/action/TransportPromoteDataStreamAction.java
@@ -21,7 +21,8 @@
 import org.elasticsearch.cluster.block.ClusterBlockException;
 import org.elasticsearch.cluster.block.ClusterBlockLevel;
 import org.elasticsearch.cluster.metadata.DataStream;
-import org.elasticsearch.cluster.metadata.Metadata;
+import org.elasticsearch.cluster.metadata.ProjectMetadata;
+import org.elasticsearch.cluster.project.ProjectResolver;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Priority;
 import org.elasticsearch.common.logging.HeaderWarning;
@@ -41,6 +42,7 @@ public class TransportPromoteDataStreamAction extends AcknowledgedTransportMaste
     private static final Logger logger = LogManager.getLogger(TransportPromoteDataStreamAction.class);
 
     private final SystemIndices systemIndices;
+    private final ProjectResolver projectResolver;
 
     @Inject
     public TransportPromoteDataStreamAction(
@@ -48,7 +50,8 @@ public TransportPromoteDataStreamAction(
         ClusterService clusterService,
         ThreadPool threadPool,
         ActionFilters actionFilters,
-        SystemIndices systemIndices
+        SystemIndices systemIndices,
+        ProjectResolver projectResolver
     ) {
         super(
             PromoteDataStreamAction.NAME,
@@ -60,6 +63,7 @@ public TransportPromoteDataStreamAction(
             EsExecutors.DIRECT_EXECUTOR_SERVICE
         );
         this.systemIndices = systemIndices;
+        this.projectResolver = projectResolver;
     }
 
     @Override
@@ -70,6 +74,7 @@ protected void masterOperation(
         ActionListener<AcknowledgedResponse> listener
     ) throws Exception {
         systemIndices.validateDataStreamAccess(request.getName(), threadPool.getThreadContext());
+        final var projectId = projectResolver.getProjectId();
         submitUnbatchedTask(
             "promote-data-stream [" + request.getName() + "]",
             new ClusterStateUpdateTask(Priority.HIGH, request.masterNodeTimeout()) {
@@ -81,7 +86,9 @@ public void onFailure(Exception e) {
 
                 @Override
                 public ClusterState execute(ClusterState currentState) {
-                    return promoteDataStream(currentState, request);
+                    final var currentProject = currentState.metadata().getProject(projectId);
+                    final var updatedProject = promoteDataStream(currentProject, request);
+                    return ClusterState.builder(currentState).putProjectMetadata(updatedProject).build();
                 }
 
                 @Override
@@ -97,27 +104,23 @@ private void submitUnbatchedTask(@SuppressWarnings("SameParameterValue") String
         clusterService.submitUnbatchedStateUpdateTask(source, task);
     }
 
-    static ClusterState promoteDataStream(ClusterState currentState, PromoteDataStreamAction.Request request) {
-        DataStream dataStream = currentState.getMetadata().getProject().dataStreams().get(request.getName());
+    static ProjectMetadata promoteDataStream(ProjectMetadata project, PromoteDataStreamAction.Request request) {
+        DataStream dataStream = project.dataStreams().get(request.getName());
 
         if (dataStream == null) {
             throw new ResourceNotFoundException("data stream [" + request.getName() + "] does not exist");
         }
 
-        warnIfTemplateMissingForDatastream(dataStream, currentState);
+        warnIfTemplateMissingForDatastream(dataStream, project);
 
         DataStream promotedDataStream = dataStream.promoteDataStream();
-        Metadata.Builder metadata = Metadata.builder(currentState.metadata());
-        metadata.put(promotedDataStream);
-        return ClusterState.builder(currentState).metadata(metadata).build();
+        return ProjectMetadata.builder(project).put(promotedDataStream).build();
     }
 
-    private static void warnIfTemplateMissingForDatastream(DataStream dataStream, ClusterState currentState) {
+    private static void warnIfTemplateMissingForDatastream(DataStream dataStream, ProjectMetadata project) {
         var datastreamName = dataStream.getName();
 
-        var matchingIndex = currentState.metadata()
-            .getProject()
-            .templatesV2()
+        var matchingIndex = project.templatesV2()
             .values()
             .stream()
             .filter(cit -> cit.getDataStreamTemplate() != null)