diff --git a/retrieval/client.go b/retrieval/client.go
index 1ba21f46a..8b21078d3 100644
--- a/retrieval/client.go
+++ b/retrieval/client.go
@@ -5,7 +5,6 @@ import (
 	"io"
 	"io/ioutil"
 
-	pb "github.com/ipfs/go-bitswap/message/pb"
 	blocks "github.com/ipfs/go-block-format"
 	"github.com/ipfs/go-cid"
 	cbor "github.com/ipfs/go-ipld-cbor"
@@ -13,7 +12,6 @@ import (
 	"github.com/libp2p/go-libp2p-core/host"
 	"github.com/libp2p/go-libp2p-core/network"
 	"github.com/libp2p/go-libp2p-core/peer"
-	"github.com/libp2p/go-msgio"
 	"golang.org/x/xerrors"
 
 	"github.com/filecoin-project/go-lotus/api"
@@ -172,42 +170,34 @@ func (cst *clientStream) doOneExchange(toFetch uint64, out io.Writer) error {
 func (cst *clientStream) fetchBlocks(toFetch uint64, out io.Writer) error {
 	blocksToFetch := (toFetch + build.UnixfsChunkSize - 1) / build.UnixfsChunkSize
 
-	// TODO: put msgio into spec
-	reader := msgio.NewVarintReaderSize(cst.stream, network.MessageSizeMax)
-
 	for i := uint64(0); i < blocksToFetch; {
 		log.Infof("block %d of %d", i+1, blocksToFetch)
-		msg, err := reader.ReadMsg()
-		if err != nil {
+
+		var block Block
+		if err := cborrpc.ReadCborRPC(cst.stream, &block); err != nil {
 			return err
 		}
 
-		var pb pb.Message_Block
-		if err := pb.Unmarshal(msg); err != nil {
-			return err
-		}
-
-		dataBlocks, err := cst.consumeBlockMessage(pb, out)
+		dataBlocks, err := cst.consumeBlockMessage(block, out)
 		if err != nil {
 			return err
 		}
 
 		i += dataBlocks
-
-		reader.ReleaseMsg(msg)
 	}
 
 	return nil
 }
 
-func (cst *clientStream) consumeBlockMessage(pb pb.Message_Block, out io.Writer) (uint64, error) {
-	prefix, err := cid.PrefixFromBytes(pb.GetPrefix())
+func (cst *clientStream) consumeBlockMessage(block Block, out io.Writer) (uint64, error) {
+	prefix, err := cid.PrefixFromBytes(block.Prefix)
 	if err != nil {
 		return 0, err
 	}
-	cid, err := prefix.Sum(pb.GetData())
 
-	blk, err := blocks.NewBlockWithCid(pb.GetData(), cid)
+	cid, err := prefix.Sum(block.Data)
+
+	blk, err := blocks.NewBlockWithCid(block.Data, cid)
 	if err != nil {
 		return 0, err
 	}
diff --git a/retrieval/miner.go b/retrieval/miner.go
index 92f27aa8b..88fba6a46 100644
--- a/retrieval/miner.go
+++ b/retrieval/miner.go
@@ -2,20 +2,19 @@ package retrieval
 
 import (
 	"context"
-	"github.com/filecoin-project/go-lotus/build"
-	"github.com/ipfs/go-cid"
-	"github.com/libp2p/go-msgio"
-	"golang.org/x/xerrors"
 	"io"
 
-	"github.com/filecoin-project/go-lotus/chain/types"
-	"github.com/filecoin-project/go-lotus/lib/cborrpc"
-	"github.com/filecoin-project/go-lotus/storage/sectorblocks"
-	pb "github.com/ipfs/go-bitswap/message/pb"
 	"github.com/ipfs/go-blockservice"
+	"github.com/ipfs/go-cid"
 	"github.com/ipfs/go-merkledag"
 	unixfile "github.com/ipfs/go-unixfs/file"
 	"github.com/libp2p/go-libp2p-core/network"
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/go-lotus/build"
+	"github.com/filecoin-project/go-lotus/chain/types"
+	"github.com/filecoin-project/go-lotus/lib/cborrpc"
+	"github.com/filecoin-project/go-lotus/storage/sectorblocks"
 )
 
 type Miner struct {
@@ -186,9 +185,6 @@ func (hnd *handlerDeal) accept(deal Deal) error {
 		return err
 	}
 
-	buf := make([]byte, network.MessageSizeMax)
-	msgw := msgio.NewVarintWriter(hnd.stream)
-
 	blocksToSend := (deal.Unixfs0.Size + build.UnixfsChunkSize - 1) / build.UnixfsChunkSize
 	for i := uint64(0); i < blocksToSend; {
 		data, offset, nd, err := hnd.ufsr.ReadBlock(context.TODO())
@@ -207,18 +203,12 @@ func (hnd *handlerDeal) accept(deal Deal) error {
 			return
 		}*/
 
-		block := pb.Message_Block{
+		block := Block{
 			Prefix: nd.Cid().Prefix().Bytes(),
 			Data:   nd.RawData(),
 		}
 
-		n, err := block.MarshalTo(buf)
-		if err != nil {
-			return err
-		}
-
-		if err := msgw.WriteMsg(buf[:n]); err != nil {
-			log.Error(err)
+		if err := cborrpc.WriteCborRPC(hnd.stream, block); err != nil {
 			return err
 		}
 
diff --git a/retrieval/types.go b/retrieval/types.go
index 765c583af..bef07c697 100644
--- a/retrieval/types.go
+++ b/retrieval/types.go
@@ -31,6 +31,7 @@ func init() {
 	cbor.RegisterCborType(Unixfs0Offer{})
 
 	cbor.RegisterCborType(DealResponse{})
+	cbor.RegisterCborType(Block{})
 }
 
 type Query struct {
@@ -62,3 +63,8 @@ type DealResponse struct {
 	Status  int // TODO: make this more spec complainant
 	Message string
 }
+
+type Block struct { // TODO: put in spec
+	Prefix []byte // TODO: fix cid.Prefix marshaling somehow
+	Data   []byte
+}