diff --git a/pkg/block/fetcher.go b/pkg/block/fetcher.go
index 4911b4748b7..1210fcc5b2d 100644
--- a/pkg/block/fetcher.go
+++ b/pkg/block/fetcher.go
@@ -11,6 +11,7 @@ import (
 	"path"
 	"path/filepath"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -24,10 +25,10 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promauto"
 	"github.com/prometheus/prometheus/model/labels"
 	"github.com/prometheus/prometheus/model/relabel"
-	"github.com/thanos-io/objstore"
 	"golang.org/x/sync/errgroup"
 	"gopkg.in/yaml.v2"
 
+	"github.com/thanos-io/objstore"
 	"github.com/thanos-io/thanos/pkg/block/metadata"
 	"github.com/thanos-io/thanos/pkg/errutil"
 	"github.com/thanos-io/thanos/pkg/extprom"
@@ -434,6 +435,10 @@ func (f *BaseFetcher) loadMeta(ctx context.Context, id ulid.ULID) (*metadata.Met
 		return nil, errors.Wrapf(ErrorSyncMetaCorrupted, "meta.json %v unmarshal: %v", metaFile, err)
 	}
 
+	if err := sanityCheckFilesForMeta(m.Thanos.Files); err != nil {
+		return nil, errors.Wrapf(ErrorSyncMetaCorrupted, "meta.json %v not sane: %v", metaFile, err)
+	}
+
 	if m.Version != metadata.TSDBVersion1 {
 		return nil, errors.Errorf("unexpected meta file: %s version: %d", metaFile, m.Version)
 	}
@@ -451,6 +456,42 @@ func (f *BaseFetcher) loadMeta(ctx context.Context, id ulid.ULID) (*metadata.Met
 	return m, nil
 }
 
+func sanityCheckFilesForMeta(files []metadata.File) error {
+	var (
+		numChunkFiles    int
+		highestChunkFile int
+		hasIndex         bool
+	)
+
+	for _, f := range files {
+		if f.RelPath == "index" {
+			hasIndex = true
+		}
+		dir, name := path.Split(f.RelPath)
+		if dir == "chunks/" {
+			numChunkFiles++
+			idx, err := strconv.Atoi(name)
+			if err != nil {
+				return errors.Wrap(err, "unexpected chunk file name")
+			}
+			if idx > highestChunkFile {
+				highestChunkFile = idx
+			}
+		}
+	}
+
+	if !hasIndex {
+		return errors.New("no index file in meta")
+	}
+	if numChunkFiles == 0 {
+		return errors.New("no chunk files in meta")
+	}
+	if numChunkFiles != highestChunkFile {
+		return errors.New("incomplete chunk files in meta")
+	}
+	return nil
+}
+
 type response struct {
 	metas   map[ulid.ULID]*metadata.Meta
 	partial map[ulid.ULID]error
diff --git a/pkg/block/fetcher_test.go b/pkg/block/fetcher_test.go
index 5e24e265382..9d4af0fb840 100644
--- a/pkg/block/fetcher_test.go
+++ b/pkg/block/fetcher_test.go
@@ -23,11 +23,11 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	promtest "github.com/prometheus/client_golang/prometheus/testutil"
 	"github.com/prometheus/prometheus/tsdb"
-	"github.com/thanos-io/objstore"
-	"github.com/thanos-io/objstore/objtesting"
 
 	"github.com/efficientgo/core/testutil"
 
+	"github.com/thanos-io/objstore"
+	"github.com/thanos-io/objstore/objtesting"
 	"github.com/thanos-io/thanos/pkg/block/metadata"
 	"github.com/thanos-io/thanos/pkg/extprom"
 	"github.com/thanos-io/thanos/pkg/model"
@@ -106,6 +106,7 @@ func TestMetaFetcher_Fetch(t *testing.T) {
 					var meta metadata.Meta
 					meta.Version = 1
 					meta.ULID = ULID(1)
+					meta.Thanos.Files = append(meta.Thanos.Files, metadata.File{RelPath: "index"}, metadata.File{RelPath: "chunks/000001"})
 
 					var buf bytes.Buffer
 					testutil.Ok(t, json.NewEncoder(&buf).Encode(&meta))
@@ -189,6 +190,7 @@ func TestMetaFetcher_Fetch(t *testing.T) {
 					var meta metadata.Meta
 					meta.Version = 1
 					meta.ULID = ULID(6)
+					meta.Thanos.Files = append(meta.Thanos.Files, metadata.File{RelPath: "index"}, metadata.File{RelPath: "chunks/000001"})
 
 					var buf bytes.Buffer
 					testutil.Ok(t, json.NewEncoder(&buf).Encode(&meta))
@@ -224,6 +226,7 @@ func TestMetaFetcher_Fetch(t *testing.T) {
 					var meta metadata.Meta
 					meta.Version = 20
 					meta.ULID = ULID(7)
+					meta.Thanos.Files = append(meta.Thanos.Files, metadata.File{RelPath: "index"}, metadata.File{RelPath: "chunks/000001"})
 
 					var buf bytes.Buffer
 					testutil.Ok(t, json.NewEncoder(&buf).Encode(&meta))
@@ -235,6 +238,64 @@ func TestMetaFetcher_Fetch(t *testing.T) {
 				expectedNoMeta:        ULIDs(4),
 				expectedMetaErr:       errors.New("incomplete view: unexpected meta file: 00000000070000000000000000/meta.json version: 20"),
 			},
+			{
+				name: "error: incomplete chunks",
+				do: func() {
+					var meta metadata.Meta
+					meta.Version = 1
+					meta.ULID = ULID(8)
+					meta.Thanos.Files = append(meta.Thanos.Files,
+						metadata.File{RelPath: "index"},
+						metadata.File{RelPath: "chunks/000001"},
+						metadata.File{RelPath: "chunks/000005"},
+					)
+
+					var buf bytes.Buffer
+					testutil.Ok(t, json.NewEncoder(&buf).Encode(&meta))
+					testutil.Ok(t, bkt.Upload(ctx, path.Join(meta.ULID.String(), metadata.MetaFilename), &buf))
+				},
+
+				expectedMetas:         ULIDs(1, 3, 6),
+				expectedCorruptedMeta: ULIDs(5, 8),
+				expectedNoMeta:        ULIDs(4),
+				expectedMetaErr:       errors.New("incomplete view: unexpected meta file: 00000000070000000000000000/meta.json version: 20"),
+			},
+			{
+				name: "error: no index",
+				do: func() {
+					var meta metadata.Meta
+					meta.Version = 1
+					meta.ULID = ULID(9)
+					meta.Thanos.Files = append(meta.Thanos.Files, metadata.File{RelPath: "chunks/000001"})
+
+					var buf bytes.Buffer
+					testutil.Ok(t, json.NewEncoder(&buf).Encode(&meta))
+					testutil.Ok(t, bkt.Upload(ctx, path.Join(meta.ULID.String(), metadata.MetaFilename), &buf))
+				},
+
+				expectedMetas:         ULIDs(1, 3, 6),
+				expectedCorruptedMeta: ULIDs(5, 8, 9),
+				expectedNoMeta:        ULIDs(4),
+				expectedMetaErr:       errors.New("incomplete view: unexpected meta file: 00000000070000000000000000/meta.json version: 20"),
+			},
+			{
+				name: "error: no chunks",
+				do: func() {
+					var meta metadata.Meta
+					meta.Version = 1
+					meta.ULID = ULID(10)
+					meta.Thanos.Files = append(meta.Thanos.Files, metadata.File{RelPath: "index"})
+
+					var buf bytes.Buffer
+					testutil.Ok(t, json.NewEncoder(&buf).Encode(&meta))
+					testutil.Ok(t, bkt.Upload(ctx, path.Join(meta.ULID.String(), metadata.MetaFilename), &buf))
+				},
+
+				expectedMetas:         ULIDs(1, 3, 6),
+				expectedCorruptedMeta: ULIDs(5, 8, 9, 10),
+				expectedNoMeta:        ULIDs(4),
+				expectedMetaErr:       errors.New("incomplete view: unexpected meta file: 00000000070000000000000000/meta.json version: 20"),
+			},
 		} {
 			if ok := t.Run(tcase.name, func(t *testing.T) {
 				tcase.do()