diff --git a/src/cmds/restic/cmd_backup.go b/src/cmds/restic/cmd_backup.go
index 4f360c9c3..53c859fd5 100644
--- a/src/cmds/restic/cmd_backup.go
+++ b/src/cmds/restic/cmd_backup.go
@@ -95,17 +95,6 @@ func formatDuration(d time.Duration) string {
 	return formatSeconds(sec)
 }
 
-func printTree2(indent int, t *restic.Tree) {
-	for _, node := range t.Nodes {
-		if node.Tree() != nil {
-			fmt.Printf("%s%s/\n", strings.Repeat("  ", indent), node.Name)
-			printTree2(indent+1, node.Tree())
-		} else {
-			fmt.Printf("%s%s\n", strings.Repeat("  ", indent), node.Name)
-		}
-	}
-}
-
 func (cmd CmdBackup) Usage() string {
 	return "DIR/FILE [DIR/FILE] [...]"
 }
diff --git a/src/cmds/restic/integration_helpers_test.go b/src/cmds/restic/integration_helpers_test.go
index 15111d688..cac3e3592 100644
--- a/src/cmds/restic/integration_helpers_test.go
+++ b/src/cmds/restic/integration_helpers_test.go
@@ -178,15 +178,6 @@ func configureRestic(t testing.TB, cache, repo string) GlobalOptions {
 	}
 }
 
-func cleanupTempdir(t testing.TB, tempdir string) {
-	if !TestCleanupTempDirs {
-		t.Logf("leaving temporary directory %v used for test", tempdir)
-		return
-	}
-
-	RemoveAll(t, tempdir)
-}
-
 // withTestEnvironment creates a test environment and calls f with it. After f has
 // returned, the temporary directory is removed.
 func withTestEnvironment(t testing.TB, f func(*testEnvironment, GlobalOptions)) {
@@ -219,13 +210,3 @@ func withTestEnvironment(t testing.TB, f func(*testEnvironment, GlobalOptions))
 
 	RemoveAll(t, tempdir)
 }
-
-// removeFile resets the read-only flag and then deletes the file.
-func removeFile(fn string) error {
-	err := os.Chmod(fn, 0666)
-	if err != nil {
-		return err
-	}
-
-	return os.Remove(fn)
-}
diff --git a/src/cmds/restic/integration_test.go b/src/cmds/restic/integration_test.go
index 0dd6c6165..56e0fc3b2 100644
--- a/src/cmds/restic/integration_test.go
+++ b/src/cmds/restic/integration_test.go
@@ -809,27 +809,6 @@ func TestRebuildIndexAlwaysFull(t *testing.T) {
 	TestRebuildIndex(t)
 }
 
-var optimizeTests = []struct {
-	testFilename string
-	snapshots    restic.IDSet
-}{
-	{
-		filepath.Join("..", "..", "restic", "checker", "testdata", "checker-test-repo.tar.gz"),
-		restic.NewIDSet(restic.TestParseID("a13c11e582b77a693dd75ab4e3a3ba96538a056594a4b9076e4cacebe6e06d43")),
-	},
-	{
-		filepath.Join("testdata", "old-index-repo.tar.gz"),
-		nil,
-	},
-	{
-		filepath.Join("testdata", "old-index-repo.tar.gz"),
-		restic.NewIDSet(
-			restic.TestParseID("f7d83db709977178c9d1a09e4009355e534cde1a135b8186b8b118a3fc4fcd41"),
-			restic.TestParseID("51d249d28815200d59e4be7b3f21a157b864dc343353df9d8e498220c2499b02"),
-		),
-	},
-}
-
 func TestCheckRestoreNoLock(t *testing.T) {
 	withTestEnvironment(t, func(env *testEnvironment, global GlobalOptions) {
 		datafile := filepath.Join("testdata", "small-repo.tar.gz")
diff --git a/src/restic/backend/test/tests.go b/src/restic/backend/test/tests.go
index e79fca366..c79d45041 100644
--- a/src/restic/backend/test/tests.go
+++ b/src/restic/backend/test/tests.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"math/rand"
 	"reflect"
 	"restic"
@@ -471,14 +470,6 @@ func store(t testing.TB, b restic.Backend, tpe restic.FileType, data []byte) {
 	test.OK(t, err)
 }
 
-func read(t testing.TB, rd io.Reader, expectedData []byte) {
-	buf, err := ioutil.ReadAll(rd)
-	test.OK(t, err)
-	if expectedData != nil {
-		test.Equals(t, expectedData, buf)
-	}
-}
-
 // TestBackend tests all functions of the backend.
 func TestBackend(t testing.TB) {
 	b := open(t)
diff --git a/src/restic/blob.go b/src/restic/blob.go
index 6074b59b1..670fd2fdf 100644
--- a/src/restic/blob.go
+++ b/src/restic/blob.go
@@ -46,6 +46,8 @@ func (t BlobType) String() string {
 		return "data"
 	case TreeBlob:
 		return "tree"
+	case InvalidBlob:
+		return "invalid"
 	}
 
 	return fmt.Sprintf("<BlobType %d>", t)
diff --git a/src/restic/checker/checker.go b/src/restic/checker/checker.go
index ebb416938..dcce67a3f 100644
--- a/src/restic/checker/checker.go
+++ b/src/restic/checker/checker.go
@@ -649,11 +649,6 @@ func (c *Checker) UnusedBlobs() (blobs restic.IDs) {
 	return blobs
 }
 
-// OrphanedPacks returns a slice of unused packs (only available after Packs() was run).
-func (c *Checker) OrphanedPacks() restic.IDs {
-	return c.orphanedPacks
-}
-
 // CountPacks returns the number of packs in the repository.
 func (c *Checker) CountPacks() uint64 {
 	return uint64(len(c.packs))
diff --git a/src/restic/checker/checker_test.go b/src/restic/checker/checker_test.go
index 2e6075be7..26528d24a 100644
--- a/src/restic/checker/checker_test.go
+++ b/src/restic/checker/checker_test.go
@@ -16,17 +16,6 @@ import (
 
 var checkerTestData = filepath.Join("testdata", "checker-test-repo.tar.gz")
 
-func list(repo restic.Repository, t restic.FileType) (IDs []string) {
-	done := make(chan struct{})
-	defer close(done)
-
-	for id := range repo.List(t, done) {
-		IDs = append(IDs, id.String())
-	}
-
-	return IDs
-}
-
 func collectErrors(f func(chan<- error, <-chan struct{})) (errs []error) {
 	done := make(chan struct{})
 	defer close(done)
diff --git a/src/restic/config.go b/src/restic/config.go
index 0afb5426b..0af6b7447 100644
--- a/src/restic/config.go
+++ b/src/restic/config.go
@@ -21,11 +21,6 @@ type Config struct {
 // is newly created with Init().
 const RepoVersion = 1
 
-// JSONUnpackedSaver saves unpacked JSON.
-type JSONUnpackedSaver interface {
-	SaveJSONUnpacked(FileType, interface{}) (ID, error)
-}
-
 // JSONUnpackedLoader loads unpacked JSON.
 type JSONUnpackedLoader interface {
 	LoadJSONUnpacked(FileType, ID, interface{}) error
diff --git a/src/restic/crypto/buffer_pool.go b/src/restic/crypto/buffer_pool.go
deleted file mode 100644
index da69b8fe3..000000000
--- a/src/restic/crypto/buffer_pool.go
+++ /dev/null
@@ -1,19 +0,0 @@
-package crypto
-
-import "sync"
-
-const defaultBufSize = 32 * 1024 // 32KiB
-
-var bufPool = sync.Pool{
-	New: func() interface{} {
-		return make([]byte, defaultBufSize)
-	},
-}
-
-func getBuffer() []byte {
-	return bufPool.Get().([]byte)
-}
-
-func freeBuffer(buf []byte) {
-	bufPool.Put(buf)
-}
diff --git a/src/restic/crypto/crypto.go b/src/restic/crypto/crypto.go
index 57fdd6230..03d3d10a2 100644
--- a/src/restic/crypto/crypto.go
+++ b/src/restic/crypto/crypto.go
@@ -26,10 +26,6 @@ const (
 var (
 	// ErrUnauthenticated is returned when ciphertext verification has failed.
 	ErrUnauthenticated = errors.New("ciphertext verification failed")
-
-	// ErrBufferTooSmall is returned when the destination slice is too small
-	// for the ciphertext.
-	ErrBufferTooSmall = errors.New("destination buffer too small")
 )
 
 // Key holds encryption and message authentication keys for a repository. It is stored
diff --git a/src/restic/id.go b/src/restic/id.go
index 6d1f55de2..08cb6f64b 100644
--- a/src/restic/id.go
+++ b/src/restic/id.go
@@ -1,7 +1,6 @@
 package restic
 
 import (
-	"bytes"
 	"crypto/rand"
 	"crypto/sha256"
 	"encoding/hex"
@@ -95,11 +94,6 @@ func (id ID) EqualString(other string) (bool, error) {
 	return id == id2, nil
 }
 
-// Compare compares this ID to another one, returning -1, 0, or 1.
-func (id ID) Compare(other ID) int {
-	return bytes.Compare(other[:], id[:])
-}
-
 // MarshalJSON returns the JSON encoding of id.
 func (id ID) MarshalJSON() ([]byte, error) {
 	return json.Marshal(id.String())
diff --git a/src/restic/index/index.go b/src/restic/index/index.go
index 9027e3fda..255e72d9e 100644
--- a/src/restic/index/index.go
+++ b/src/restic/index/index.go
@@ -77,8 +77,6 @@ func New(repo restic.Repository, p *restic.Progress) (*Index, error) {
 	return idx, nil
 }
 
-const loadIndexParallelism = 20
-
 type packJSON struct {
 	ID    restic.ID  `json:"id"`
 	Blobs []blobJSON `json:"blobs"`
diff --git a/src/restic/index/index_test.go b/src/restic/index/index_test.go
index 608ff944a..7905f7368 100644
--- a/src/restic/index/index_test.go
+++ b/src/restic/index/index_test.go
@@ -10,7 +10,6 @@ import (
 
 var (
 	snapshotTime = time.Unix(1470492820, 207401672)
-	snapshots    = 3
 	depth        = 3
 )
 
diff --git a/src/restic/node.go b/src/restic/node.go
index 0a8624f5d..19f6583eb 100644
--- a/src/restic/node.go
+++ b/src/restic/node.go
@@ -40,10 +40,7 @@ type Node struct {
 
 	Error string `json:"error,omitempty"`
 
-	tree *Tree
-
 	Path string `json:"-"`
-	err  error
 }
 
 func (node Node) String() string {
@@ -59,11 +56,6 @@ func (node Node) String() string {
 	return fmt.Sprintf("<Node(%s) %s>", node.Type, node.Name)
 }
 
-// Tree returns this node's tree object.
-func (node Node) Tree() *Tree {
-	return node.tree
-}
-
 // NodeFromFileInfo returns a new node from the given path and FileInfo.
 func NodeFromFileInfo(path string, fi os.FileInfo) (*Node, error) {
 	mask := os.ModePerm | os.ModeType | os.ModeSetuid | os.ModeSetgid | os.ModeSticky
diff --git a/src/restic/pipe/pipe.go b/src/restic/pipe/pipe.go
index 1ed9b6162..5db01375b 100644
--- a/src/restic/pipe/pipe.go
+++ b/src/restic/pipe/pipe.go
@@ -74,12 +74,6 @@ func readDirNames(dirname string) ([]string, error) {
 	return names, nil
 }
 
-func isDir(fi os.FileInfo) bool {
-	return fi.IsDir()
-}
-
-var errCancelled = errors.New("walk cancelled")
-
 // SelectFunc returns true for all items that should be included (files and
 // dirs). If false is returned, files are ignored and dirs are not even walked.
 type SelectFunc func(item string, fi os.FileInfo) bool
diff --git a/src/restic/pipe/pipe_test.go b/src/restic/pipe/pipe_test.go
index 719670aaa..dd2c5e02d 100644
--- a/src/restic/pipe/pipe_test.go
+++ b/src/restic/pipe/pipe_test.go
@@ -14,10 +14,6 @@ import (
 	. "restic/test"
 )
 
-func isFile(fi os.FileInfo) bool {
-	return fi.Mode()&(os.ModeType|os.ModeCharDevice) == 0
-}
-
 type stats struct {
 	dirs, files int
 }
diff --git a/src/restic/repository/index.go b/src/restic/repository/index.go
index 029374063..fb7ff1ee5 100644
--- a/src/restic/repository/index.go
+++ b/src/restic/repository/index.go
@@ -275,15 +275,6 @@ func (idx *Index) Count(t restic.BlobType) (n uint) {
 	return
 }
 
-// Length returns the number of entries in the Index.
-func (idx *Index) Length() uint {
-	debug.Log("Index.Count", "counting blobs")
-	idx.m.Lock()
-	defer idx.m.Unlock()
-
-	return uint(len(idx.pack))
-}
-
 type packJSON struct {
 	ID    restic.ID  `json:"id"`
 	Blobs []blobJSON `json:"blobs"`
@@ -346,8 +337,6 @@ type jsonIndex struct {
 	Packs      []*packJSON `json:"packs"`
 }
 
-type jsonOldIndex []*packJSON
-
 // Encode writes the JSON serialization of the index to the writer w.
 func (idx *Index) Encode(w io.Writer) error {
 	debug.Log("Index.Encode", "encoding index")
@@ -552,28 +541,3 @@ func LoadIndexWithDecoder(repo restic.Repository, id restic.ID, fn func(io.Reade
 
 	return idx, nil
 }
-
-// ConvertIndex loads the given index from the repo and converts them to the new
-// format (if necessary). When the conversion is succcessful, the old index
-// is removed. Returned is either the old id (if no conversion was needed) or
-// the new id.
-func ConvertIndex(repo *Repository, id restic.ID) (restic.ID, error) {
-	debug.Log("ConvertIndex", "checking index %v", id.Str())
-
-	idx, err := LoadIndexWithDecoder(repo, id, DecodeOldIndex)
-	if err != nil {
-		debug.Log("ConvertIndex", "LoadIndexWithDecoder(%v) returned error: %v", id.Str(), err)
-		return id, err
-	}
-
-	buf := bytes.NewBuffer(nil)
-	idx.supersedes = restic.IDs{id}
-
-	err = idx.Encode(buf)
-	if err != nil {
-		debug.Log("ConvertIndex", "oldIdx.Encode() returned error: %v", err)
-		return id, err
-	}
-
-	return repo.SaveUnpacked(restic.IndexFile, buf.Bytes())
-}
diff --git a/src/restic/repository/repository.go b/src/restic/repository/repository.go
index a7258e090..7097dc200 100644
--- a/src/restic/repository/repository.go
+++ b/src/restic/repository/repository.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	"io"
 	"os"
 	"restic"
 
@@ -43,13 +42,6 @@ func (r *Repository) Config() restic.Config {
 	return r.cfg
 }
 
-// Find loads the list of all blobs of type t and searches for names which start
-// with prefix. If none is found, nil and ErrNoIDPrefixFound is returned. If
-// more than one is found, nil and ErrMultipleIDMatches is returned.
-func (r *Repository) Find(t restic.FileType, prefix string) (string, error) {
-	return restic.Find(r.be, t, prefix)
-}
-
 // PrefixLength returns the number of bytes required so that all prefixes of
 // all IDs of type t are unique.
 func (r *Repository) PrefixLength(t restic.FileType) (int, error) {
@@ -156,16 +148,6 @@ func (r *Repository) loadBlob(id restic.ID, t restic.BlobType, plaintextBuf []by
 	return 0, errors.Errorf("loading blob %v from %v packs failed", id.Str(), len(blobs))
 }
 
-// closeOrErr calls cl.Close() and sets err to the returned error value if
-// itself is not yet set.
-func closeOrErr(cl io.Closer, err *error) {
-	e := cl.Close()
-	if *err != nil {
-		return
-	}
-	*err = e
-}
-
 // LoadJSONUnpacked decrypts the data and afterwards calls json.Unmarshal on
 // the item.
 func (r *Repository) LoadJSONUnpacked(t restic.FileType, id restic.ID, item interface{}) (err error) {
diff --git a/src/restic/repository/repository_test.go b/src/restic/repository/repository_test.go
index ce4fb68ed..5934d4778 100644
--- a/src/restic/repository/repository_test.go
+++ b/src/restic/repository/repository_test.go
@@ -234,11 +234,6 @@ func TestRepositoryIncrementalIndex(t *testing.T) {
 	// save final index
 	OK(t, repo.SaveIndex())
 
-	type packEntry struct {
-		id      restic.ID
-		indexes []*repository.Index
-	}
-
 	packEntries := make(map[restic.ID]map[restic.ID]struct{})
 
 	for id := range repo.List(restic.IndexFile, nil) {
diff --git a/src/restic/test/helpers.go b/src/restic/test/helpers.go
index d363e09c9..22489df01 100644
--- a/src/restic/test/helpers.go
+++ b/src/restic/test/helpers.go
@@ -3,7 +3,6 @@ package test
 import (
 	"compress/bzip2"
 	"compress/gzip"
-	"crypto/rand"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -90,56 +89,6 @@ func Random(seed, count int) []byte {
 	return p
 }
 
-type rndReader struct {
-	src *mrand.Rand
-}
-
-func (r *rndReader) Read(p []byte) (int, error) {
-	for i := 0; i < len(p); i += 8 {
-		val := r.src.Int63()
-		var data = []byte{
-			byte((val >> 0) & 0xff),
-			byte((val >> 8) & 0xff),
-			byte((val >> 16) & 0xff),
-			byte((val >> 24) & 0xff),
-			byte((val >> 32) & 0xff),
-			byte((val >> 40) & 0xff),
-			byte((val >> 48) & 0xff),
-			byte((val >> 56) & 0xff),
-		}
-
-		for j := range data {
-			cur := i + j
-			if len(p) >= cur {
-				break
-			}
-			p[cur] = data[j]
-		}
-	}
-
-	return len(p), nil
-}
-
-// RandomReader returns a reader that returns deterministic pseudo-random data
-// derived from the seed.
-func RandomReader(seed int) io.Reader {
-	return &rndReader{src: mrand.New(mrand.NewSource(int64(seed)))}
-}
-
-// RandomLimitReader returns a reader that returns size bytes of deterministic
-// pseudo-random data derived from the seed.
-func RandomLimitReader(seed, size int) io.Reader {
-	return io.LimitReader(RandomReader(seed), int64(size))
-}
-
-// GenRandom returns a []byte filled with up to 1000 random bytes.
-func GenRandom(t testing.TB) []byte {
-	buf := make([]byte, mrand.Intn(1000))
-	_, err := io.ReadFull(rand.Reader, buf)
-	OK(t, err)
-	return buf
-}
-
 // SetupTarTestFixture extracts the tarFile to outputDir.
 func SetupTarTestFixture(t testing.TB, outputDir, tarFile string) {
 	input, err := os.Open(tarFile)
diff --git a/src/restic/tree.go b/src/restic/tree.go
index f2c1c04a9..c88141b91 100644
--- a/src/restic/tree.go
+++ b/src/restic/tree.go
@@ -71,12 +71,6 @@ func (t Tree) binarySearch(name string) (int, *Node, error) {
 	return pos, nil, errors.New("named node not found")
 }
 
-// Find returns a node with the given name.
-func (t Tree) Find(name string) (*Node, error) {
-	_, node, err := t.binarySearch(name)
-	return node, err
-}
-
 // Subtrees returns a slice of all subtree IDs of the tree.
 func (t Tree) Subtrees() (trees IDs) {
 	for _, node := range t.Nodes {
diff --git a/src/restic/worker/pool.go b/src/restic/worker/pool.go
index d2331f587..2268ef8f8 100644
--- a/src/restic/worker/pool.go
+++ b/src/restic/worker/pool.go
@@ -94,11 +94,6 @@ func (p *Pool) runWorker(numWorker int) {
 	}
 }
 
-// Cancel signals termination to all worker goroutines.
-func (p *Pool) Cancel() {
-	close(p.done)
-}
-
 // Wait waits for all worker goroutines to terminate, afterwards the output
 // channel is closed.
 func (p *Pool) Wait() {