diff --git a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/70_bulk.yml b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/70_bulk.yml
index 99d5be73bc00a..0c18cd8814bbf 100644
--- a/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/70_bulk.yml
+++ b/modules/ingest-common/src/yamlRestTest/resources/rest-api-spec/test/ingest/70_bulk.yml
@@ -237,6 +237,12 @@ teardown:
               _index: test_index
               _id:    test_id2
           - f1: v2
+          - index:
+              _index: test_index
+              _id:    test_id2
+              pipeline: fake_pipeline
+          - f1: v2
 
   - match: { items.0.index.executed_pipelines: ["pipeline1"] }
   - match: { items.1.index.executed_pipelines: [] }
+  - match: { items.2.index.executed_pipelines: null }
diff --git a/server/src/main/java/org/elasticsearch/action/index/IndexRequest.java b/server/src/main/java/org/elasticsearch/action/index/IndexRequest.java
index 3de9526ef8fac..2f202dd21ad7c 100644
--- a/server/src/main/java/org/elasticsearch/action/index/IndexRequest.java
+++ b/server/src/main/java/org/elasticsearch/action/index/IndexRequest.java
@@ -183,7 +183,10 @@ public IndexRequest(@Nullable ShardId shardId, StreamInput in) throws IOExceptio
         if (in.getTransportVersion().onOrAfter(TransportVersions.PIPELINES_IN_BULK_RESPONSE_ADDED)) {
             this.listExecutedPipelines = in.readBoolean();
             if (listExecutedPipelines) {
-                this.executedPipelines = new ArrayList<>(in.readCollectionAsList(StreamInput::readString));
+                List<String> possiblyImmutableExecutedPipelines = in.readOptionalCollectionAsList(StreamInput::readString);
+                this.executedPipelines = possiblyImmutableExecutedPipelines == null
+                    ? null
+                    : new ArrayList<>(possiblyImmutableExecutedPipelines);
             }
         }
     }
@@ -749,7 +752,7 @@ private void writeBody(StreamOutput out) throws IOException {
         if (out.getTransportVersion().onOrAfter(TransportVersions.PIPELINES_IN_BULK_RESPONSE_ADDED)) {
             out.writeBoolean(listExecutedPipelines);
             if (listExecutedPipelines) {
-                out.writeCollection(executedPipelines, StreamOutput::writeString);
+                out.writeOptionalCollection(executedPipelines, StreamOutput::writeString);
             }
         }
     }