diff --git a/src/cmds/restic/cmd_init.go b/src/cmds/restic/cmd_init.go
index ec790fe90..069977cb6 100644
--- a/src/cmds/restic/cmd_init.go
+++ b/src/cmds/restic/cmd_init.go
@@ -26,7 +26,11 @@ func (cmd CmdInit) Execute(args []string) error {
 			"enter password again: ")
 	}
 
-	s := repository.New(be)
+	s, err := repository.New(be)
+	if err != nil {
+		return err
+	}
+
 	err = s.Init(cmd.global.password)
 	if err != nil {
 		cmd.global.Exitf(1, "creating key in backend at %s failed: %v\n", cmd.global.Repo, err)
diff --git a/src/cmds/restic/global.go b/src/cmds/restic/global.go
index 49a2ace30..1de0bfe76 100644
--- a/src/cmds/restic/global.go
+++ b/src/cmds/restic/global.go
@@ -208,7 +208,10 @@ func (o GlobalOptions) OpenRepository() (*repository.Repository, error) {
 		return nil, err
 	}
 
-	s := repository.New(be)
+	s, err := repository.New(be)
+	if err != nil {
+		return nil, err
+	}
 
 	if o.password == "" {
 		o.password = o.ReadPassword("enter password for repository: ")
diff --git a/src/restic/archiver_duplication_test.go b/src/restic/archiver_duplication_test.go
index 3edc70cb3..564cdca00 100644
--- a/src/restic/archiver_duplication_test.go
+++ b/src/restic/archiver_duplication_test.go
@@ -78,7 +78,11 @@ func testArchiverDuplication(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	repo := repository.New(forgetfulBackend())
+	repo, err := repository.New(forgetfulBackend())
+	if err != nil {
+		t.Fatal(err)
+	}
+
 	err = repo.Init("foo")
 	if err != nil {
 		t.Fatal(err)
diff --git a/src/restic/checker/checker_test.go b/src/restic/checker/checker_test.go
index 85135a98c..5db7d945e 100644
--- a/src/restic/checker/checker_test.go
+++ b/src/restic/checker/checker_test.go
@@ -239,7 +239,8 @@ func induceError(data []byte) {
 func TestCheckerModifiedData(t *testing.T) {
 	be := mem.New()
 
-	repo := repository.New(be)
+	repo, err := repository.New(be)
+	OK(t, err)
 	OK(t, repo.Init(TestPassword))
 
 	arch := restic.NewArchiver(repo)
@@ -248,7 +249,8 @@ func TestCheckerModifiedData(t *testing.T) {
 	t.Logf("archived as %v", id.Str())
 
 	beError := &errorBackend{Backend: be}
-	checkRepo := repository.New(beError)
+	checkRepo, err := repository.New(beError)
+	OK(t, err)
 	OK(t, checkRepo.SearchKey(TestPassword))
 
 	chkr := checker.New(checkRepo)
diff --git a/src/restic/pack/pack.go b/src/restic/pack/pack.go
index e983eae3f..931bda869 100644
--- a/src/restic/pack/pack.go
+++ b/src/restic/pack/pack.go
@@ -91,6 +91,9 @@ type Packer struct {
 // NewPacker returns a new Packer that can be used to pack blobs
 // together. If wr is nil, a bytes.Buffer is used.
 func NewPacker(k *crypto.Key, wr io.Writer) *Packer {
+	if wr == nil {
+		wr = bytes.NewBuffer(nil)
+	}
 	return &Packer{k: k, wr: wr}
 }
 
diff --git a/src/restic/pack/pack_test.go b/src/restic/pack/pack_test.go
index 18a7a86f4..e987ced7c 100644
--- a/src/restic/pack/pack_test.go
+++ b/src/restic/pack/pack_test.go
@@ -38,12 +38,13 @@ func newPack(t testing.TB, k *crypto.Key) ([]Buf, []byte, uint) {
 	// pack blobs
 	p := pack.NewPacker(k, nil)
 	for _, b := range bufs {
-		p.Add(pack.Tree, b.id, bytes.NewReader(b.data))
+		p.Add(pack.Tree, b.id, b.data)
 	}
 
-	packData, err := p.Finalize()
+	_, err := p.Finalize()
 	OK(t, err)
 
+	packData := p.Writer().(*bytes.Buffer).Bytes()
 	return bufs, packData, p.Size()
 }