diff --git a/src/client/http_client.rs b/src/client/http_client.rs
index 1793e432..3f78b2e3 100644
--- a/src/client/http_client.rs
+++ b/src/client/http_client.rs
@@ -503,7 +503,7 @@ impl BackupClient {
     }
 
     fn upload_chunk_queue(h2: H2Client, wid: u64) -> (
-        mpsc::Sender<MergedChunkInfo>,
+        mpsc::Sender<(MergedChunkInfo, Option<h2::client::ResponseFuture>)>,
         sync::oneshot::Receiver<Result<(), Error>>
     ) {
         let (verify_queue_tx, verify_queue_rx) = mpsc::channel(100);
@@ -514,33 +514,22 @@ impl BackupClient {
         hyper::rt::spawn(
             verify_queue_rx
                 .map_err(Error::from)
-                .and_then(move |merged_chunk_info| {
-                    match merged_chunk_info {
-                        MergedChunkInfo::New(chunk_info) => {
-                            let offset = chunk_info.offset;
-                            let digest = chunk_info.digest;
-                            println!("upload new chunk {} ({} bytes, offset {})", tools::digest_to_hex(&digest),
-                                     chunk_info.data.len(), offset);
-                            let param = json!({ "wid": wid, "offset": offset, "size" : chunk_info.data.len() });
-                            let request = H2Client::request_builder("localhost", "POST", "dynamic_chunk", Some(param)).unwrap();
-                            let upload_data = Some(chunk_info.data.freeze());
-
+                .and_then(move |(merged_chunk_info, response): (MergedChunkInfo, Option<h2::client::ResponseFuture>)| {
+                    match (response, merged_chunk_info) {
+                        (Some(response), MergedChunkInfo::Known(list)) => {
                             future::Either::A(
-                                h2.send_request(request, upload_data)
-                                    .and_then(move |response| {
-                                        response
-                                            .map_err(Error::from)
-                                            .and_then(H2Client::h2api_response)
-                                            .and_then(move |result| {
-                                                Ok(MergedChunkInfo::Known(vec![(offset, digest)]))
-                                            })
+                                response
+                                    .map_err(Error::from)
+                                    .and_then(H2Client::h2api_response)
+                                    .and_then(move |result| {
+                                        Ok(MergedChunkInfo::Known(list))
                                     })
-                                    .map_err(|err| format_err!("pipelined request failed: {}", err))
                             )
                         }
-                        MergedChunkInfo::Known(list) => {
+                        (None, MergedChunkInfo::Known(list)) => {
                             future::Either::B(future::ok(MergedChunkInfo::Known(list)))
                         }
+                        _ => unreachable!(),
                     }
                 })
                 .merge_known_chunks()
@@ -654,8 +643,35 @@ impl BackupClient {
             })
             .merge_known_chunks()
             .for_each(move |merged_chunk_info| {
-                upload_queue.clone().send(merged_chunk_info)
-                    .map(|_| ()).map_err(Error::from)
+
+                if let MergedChunkInfo::New(chunk_info) = merged_chunk_info {
+                    let offset = chunk_info.offset;
+                    let digest = chunk_info.digest;
+                    let upload_queue = upload_queue.clone();
+
+                    println!("upload new chunk {} ({} bytes, offset {})", tools::digest_to_hex(&digest),
+                             chunk_info.data.len(), offset);
+
+                    let param = json!({ "wid": wid, "offset": offset, "size" : chunk_info.data.len() });
+                    let request = H2Client::request_builder("localhost", "POST", "dynamic_chunk", Some(param)).unwrap();
+                    let upload_data = Some(chunk_info.data.freeze());
+
+                    let new_info = MergedChunkInfo::Known(vec![(chunk_info.offset, chunk_info.digest)]);
+
+                    future::Either::A(
+                        h2.send_request(request, upload_data)
+                            .and_then(move |response| {
+                                upload_queue.clone().send((new_info, Some(response)))
+                                    .map(|_| ()).map_err(Error::from)
+                            })
+                    )
+                } else {
+
+                    future::Either::B(
+                        upload_queue.clone().send((merged_chunk_info, None))
+                            .map(|_| ()).map_err(Error::from)
+                    )
+                }
             })
             .then(move |result| {
                 println!("RESULT {:?}", result);