diff --git a/core/src/main/java/org/elasticsearch/action/DocumentWriteRequest.java b/core/src/main/java/org/elasticsearch/action/DocumentWriteRequest.java
index 66ea6401bcc..490aa7fd326 100644
--- a/core/src/main/java/org/elasticsearch/action/DocumentWriteRequest.java
+++ b/core/src/main/java/org/elasticsearch/action/DocumentWriteRequest.java
@@ -178,6 +178,7 @@ public abstract class DocumentWriteRequest<T extends ReplicatedWriteRequest<T>>
 
     /** write a document write (index/delete/update) request*/
     public static void writeDocumentRequest(StreamOutput out, DocumentWriteRequest request)  throws IOException {
+        assert request != null : "request must not be null";
         if (request instanceof IndexRequest) {
             out.writeByte((byte) 0);
         } else if (request instanceof DeleteRequest) {
diff --git a/core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java b/core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java
index 9a58817c188..b25483268fa 100644
--- a/core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java
+++ b/core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java
@@ -168,7 +168,7 @@ public class TransportShardBulkAction extends TransportWriteAction<BulkShardRequ
                                                      BulkShardRequest request,
                                                      long[] preVersions, VersionType[] preVersionTypes,
                                                      Translog.Location location, int requestIndex) {
-        DocumentWriteRequest<?> itemRequest = request.items()[requestIndex].request();
+        DocumentWriteRequest itemRequest = request.items()[requestIndex].request();
         preVersions[requestIndex] = itemRequest.version();
         preVersionTypes[requestIndex] = itemRequest.versionType();
         DocumentWriteRequest.OpType opType = itemRequest.opType();
@@ -196,9 +196,14 @@ public class TransportShardBulkAction extends TransportWriteAction<BulkShardRequ
                 assert writeResult.getResponse().getResult() == DocWriteResponse.Result.NOOP
                         : "only noop operation can have null next operation";
             }
+            assert !(writeResult.getReplicaRequest() instanceof BulkShardRequest) : "replication request must be a single document operation";
             // update the bulk item request with replica request (update request are changed to index or delete requests for replication)
-            request.items()[requestIndex] = new BulkItemRequest(request.items()[requestIndex].id(),
-                    (DocumentWriteRequest<?>) writeResult.getReplicaRequest());
+            DocumentWriteRequest replicaRequest = (DocumentWriteRequest) writeResult.getReplicaRequest();
+            if (replicaRequest != null) {
+                request.items()[requestIndex] = new BulkItemRequest(request.items()[requestIndex].id(), replicaRequest);
+            } else {
+                request.items()[requestIndex].setIgnoreOnReplica();
+            }
             // add the response
             setResponse(request.items()[requestIndex], new BulkItemResponse(request.items()[requestIndex].id(), opType, writeResult.getResponse()));
         } catch (Exception e) {
@@ -206,14 +211,14 @@ public class TransportShardBulkAction extends TransportWriteAction<BulkShardRequ
             if (retryPrimaryException(e)) {
                 // restore updated versions...
                 for (int j = 0; j < requestIndex; j++) {
-                    DocumentWriteRequest<?> documentWriteRequest = request.items()[j].request();
+                    DocumentWriteRequest documentWriteRequest = request.items()[j].request();
                     documentWriteRequest.version(preVersions[j]);
                     documentWriteRequest.versionType(preVersionTypes[j]);
                 }
                 throw (ElasticsearchException) e;
             }
             BulkItemRequest item = request.items()[requestIndex];
-            DocumentWriteRequest<?> documentWriteRequest = item.request();
+            DocumentWriteRequest documentWriteRequest = item.request();
             if (isConflictException(e)) {
                 logger.trace((Supplier<?>) () -> new ParameterizedMessage("{} failed to execute bulk item ({}) {}",
                         request.shardId(), documentWriteRequest.opType().getLowercase(), request), e);