diff --git a/chunks.go b/chunks.go
index aa44b259e687af7a64a4bf88fb7409e33bce0acb..5063a20e7a2a858c88b8d5db9a7b78edd8b16e39 100644
--- a/chunks.go
+++ b/chunks.go
@@ -17,8 +17,6 @@ import (
 	"bufio"
 	"encoding/binary"
 	"fmt"
-	"hash"
-	"hash/crc32"
 	"io"
 	"os"
 
@@ -63,7 +61,6 @@ type chunkWriter struct {
 	files   []*os.File
 	wbuf    *bufio.Writer
 	n       int64
-	crc32   hash.Hash
 
 	segmentSize int64
 }
@@ -85,7 +82,6 @@ func newChunkWriter(dir string) (*chunkWriter, error) {
 	cw := &chunkWriter{
 		dirFile:     dirFile,
 		n:           0,
-		crc32:       crc32.New(crc32.MakeTable(crc32.Castagnoli)),
 		segmentSize: defaultChunkSegmentSize,
 	}
 	return cw, nil
@@ -165,8 +161,8 @@ func (w *chunkWriter) cut() error {
 	return nil
 }
 
-func (w *chunkWriter) write(wr io.Writer, b []byte) error {
-	n, err := wr.Write(b)
+func (w *chunkWriter) write(b []byte) error {
+	n, err := w.wbuf.Write(b)
 	w.n += int64(n)
 	return err
 }
@@ -187,14 +183,10 @@ func (w *chunkWriter) WriteChunks(chks ...*ChunkMeta) error {
 		}
 	}
 
-	// Write chunks sequentially and set the reference field in the ChunkMeta.
-	w.crc32.Reset()
-	wr := io.MultiWriter(w.crc32, w.wbuf)
-
 	b := make([]byte, binary.MaxVarintLen32)
 	n := binary.PutUvarint(b, uint64(len(chks)))
 
-	if err := w.write(wr, b[:n]); err != nil {
+	if err := w.write(b[:n]); err != nil {
 		return err
 	}
 	seq := uint64(w.seq()) << 32
@@ -204,21 +196,17 @@ func (w *chunkWriter) WriteChunks(chks ...*ChunkMeta) error {
 
 		n = binary.PutUvarint(b, uint64(len(chk.Chunk.Bytes())))
 
-		if err := w.write(wr, b[:n]); err != nil {
+		if err := w.write(b[:n]); err != nil {
 			return err
 		}
-		if err := w.write(wr, []byte{byte(chk.Chunk.Encoding())}); err != nil {
+		if err := w.write([]byte{byte(chk.Chunk.Encoding())}); err != nil {
 			return err
 		}
-		if err := w.write(wr, chk.Chunk.Bytes()); err != nil {
+		if err := w.write(chk.Chunk.Bytes()); err != nil {
 			return err
 		}
-		chk.Chunk = nil
 	}
 
-	if err := w.write(w.wbuf, w.crc32.Sum(nil)); err != nil {
-		return err
-	}
 	return nil
 }
 
diff --git a/index.go b/index.go
index 73b65da306b8cd068758a6a7bae74e22394613f9..9f3da5019ed4d7c760f443f440c6a8372393bc23 100644
--- a/index.go
+++ b/index.go
@@ -228,7 +228,8 @@ func (w *indexWriter) writeSeries() error {
 
 	for _, s := range series {
 		// Write label set symbol references.
-		s.offset = base + uint32(len(w.b))
+		start := len(w.b)
+		s.offset = base + uint32(start)
 
 		n := binary.PutUvarint(buf, uint64(len(s.labels)))
 		w.b = append(w.b, buf[:n]...)
@@ -253,6 +254,22 @@ func (w *indexWriter) writeSeries() error {
 			n = binary.PutUvarint(buf, uint64(c.Ref))
 			w.b = append(w.b, buf[:n]...)
 		}
+
+		// Write checksum over series index entry and all its chunk data.
+		w.crc32.Reset()
+		w.crc32.Write(w.b[start:])
+
+		for _, c := range s.chunks {
+			fmt.Println(c)
+			if _, err := w.crc32.Write([]byte{byte(c.Chunk.Encoding())}); err != nil {
+				return err
+			}
+			if _, err := w.crc32.Write(c.Chunk.Bytes()); err != nil {
+				return err
+			}
+		}
+
+		w.b = append(w.b, w.crc32.Sum(nil)...)
 	}
 
 	return w.section(len(w.b), flagStd, func(wr io.Writer) error {
diff --git a/index_test.go b/index_test.go
index 3522ca68ed7ef742c44493e62f33b3878e8d85f6..b38350dcf79fcf9c6ea29a4f8fb1e448e8810183 100644
--- a/index_test.go
+++ b/index_test.go
@@ -22,6 +22,7 @@ import (
 	"testing"
 
 	"github.com/pkg/errors"
+	"github.com/prometheus/tsdb/chunks"
 	"github.com/prometheus/tsdb/labels"
 	"github.com/stretchr/testify/require"
 )
@@ -50,10 +51,14 @@ func (m mockIndex) AddSeries(ref uint32, l labels.Labels, chunks ...*ChunkMeta)
 		return errors.Errorf("series with reference %d already added", ref)
 	}
 
-	m.series[ref] = series{
-		l:      l,
-		chunks: chunks,
+	s := series{l: l}
+	// Actual chunk data is not stored in the index.
+	for _, c := range chunks {
+		cc := *c
+		cc.Chunk = nil
+		s.chunks = append(s.chunks, &cc)
 	}
+	m.series[ref] = s
 
 	return nil
 }
@@ -241,6 +246,7 @@ func TestPersistence_index_e2e(t *testing.T) {
 				MinTime: int64(j * 10000),
 				MaxTime: int64((j + 1) * 10000),
 				Ref:     rand.Uint64(),
+				Chunk:   chunks.NewXORChunk(),
 			})
 		}
 		input = append(input, &indexWriterSeries{