diff --git a/Vagrantfile b/Vagrantfile
index ae66663bb..b12f1a737 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -85,6 +85,7 @@ end
 Vagrant.configure(2) do |config|
   # use rsync to copy content to the folder
   config.vm.synced_folder ".", "/vagrant/go/src/github.com/restic/restic", :type => "rsync"
+  config.vm.synced_folder ".", "/vagrant", disabled: true
 
   # fix permissions on synced folder
   config.vm.provision "fix perms", :type => :shell, :inline => fix_perms
diff --git a/cmd/restic/integration_fuse_test.go b/cmd/restic/integration_fuse_test.go
index 5a6d26ac9..807b335fc 100644
--- a/cmd/restic/integration_fuse_test.go
+++ b/cmd/restic/integration_fuse_test.go
@@ -57,7 +57,7 @@ func cmdMount(t testing.TB, global GlobalOptions, dir string, ready, done chan s
 	cmd := &CmdMount{global: &global, ready: ready, done: done}
 	OK(t, cmd.Execute([]string{dir}))
 	if TestCleanup {
-		OK(t, os.RemoveAll(dir))
+		RemoveAll(t, dir)
 	}
 }
 
@@ -102,7 +102,7 @@ func TestMount(t *testing.T) {
 		OK(t, err)
 
 		// We remove the mountpoint now to check that cmdMount creates it
-		OK(t, os.RemoveAll(mountpoint))
+		RemoveAll(t, mountpoint)
 
 		ready := make(chan struct{}, 1)
 		done := make(chan struct{})
diff --git a/cmd/restic/integration_helpers_test.go b/cmd/restic/integration_helpers_test.go
index a31198a53..857096c58 100644
--- a/cmd/restic/integration_helpers_test.go
+++ b/cmd/restic/integration_helpers_test.go
@@ -183,7 +183,7 @@ func cleanupTempdir(t testing.TB, tempdir string) {
 		return
 	}
 
-	OK(t, os.RemoveAll(tempdir))
+	RemoveAll(t, tempdir)
 }
 
 // withTestEnvironment creates a test environment and calls f with it. After f has
@@ -214,5 +214,5 @@ func withTestEnvironment(t testing.TB, f func(*testEnvironment, GlobalOptions))
 		return
 	}
 
-	OK(t, os.RemoveAll(tempdir))
+	RemoveAll(t, tempdir)
 }
diff --git a/crypto/crypto_test.go b/crypto/crypto_test.go
index f255181ba..50895c65c 100644
--- a/crypto/crypto_test.go
+++ b/crypto/crypto_test.go
@@ -2,9 +2,9 @@ package crypto_test
 
 import (
 	"bytes"
+	"crypto/rand"
 	"io"
 	"io/ioutil"
-	"os"
 	"testing"
 
 	"github.com/restic/chunker"
@@ -50,10 +50,7 @@ func TestSmallBuffer(t *testing.T) {
 
 	size := 600
 	data := make([]byte, size)
-	f, err := os.Open("/dev/urandom")
-	OK(t, err)
-
-	_, err = io.ReadFull(f, data)
+	_, err := io.ReadFull(rand.Reader, data)
 	OK(t, err)
 
 	ciphertext := make([]byte, size/2)
@@ -75,10 +72,7 @@ func TestSameBuffer(t *testing.T) {
 
 	size := 600
 	data := make([]byte, size)
-	f, err := os.Open("/dev/urandom")
-	OK(t, err)
-
-	_, err = io.ReadFull(f, data)
+	_, err := io.ReadFull(rand.Reader, data)
 	OK(t, err)
 
 	ciphertext := make([]byte, 0, size+crypto.Extension)
@@ -124,10 +118,7 @@ func TestLargeEncrypt(t *testing.T) {
 
 	for _, size := range []int{chunker.MaxSize, chunker.MaxSize + 1, chunker.MaxSize + 1<<20} {
 		data := make([]byte, size)
-		f, err := os.Open("/dev/urandom")
-		OK(t, err)
-
-		_, err = io.ReadFull(f, data)
+		_, err := io.ReadFull(rand.Reader, data)
 		OK(t, err)
 
 		ciphertext, err := crypto.Encrypt(k, make([]byte, size+crypto.Extension), data)
diff --git a/fuse/dir.go b/fuse/dir.go
index 7588b31e6..19f5d569f 100644
--- a/fuse/dir.go
+++ b/fuse/dir.go
@@ -1,3 +1,6 @@
+// +build !openbsd
+// +build !windows
+
 package fuse
 
 import (
diff --git a/fuse/file.go b/fuse/file.go
index 20e6fdd16..998ea822c 100644
--- a/fuse/file.go
+++ b/fuse/file.go
@@ -1,3 +1,6 @@
+// +build !openbsd
+// +build !windows
+
 package fuse
 
 import (
diff --git a/fuse/file_test.go b/fuse/file_test.go
index db48f1e9d..10668ea82 100644
--- a/fuse/file_test.go
+++ b/fuse/file_test.go
@@ -1,3 +1,6 @@
+// +build !openbsd
+// +build !windows
+
 package fuse
 
 import (
diff --git a/fuse/fuse.go b/fuse/fuse.go
index 487d23f10..da64f3938 100644
--- a/fuse/fuse.go
+++ b/fuse/fuse.go
@@ -1,3 +1,6 @@
+// +build !openbsd
+// +build !windows
+
 package fuse
 
 import (
diff --git a/fuse/link.go b/fuse/link.go
index 61e05b3fd..f963b5832 100644
--- a/fuse/link.go
+++ b/fuse/link.go
@@ -1,3 +1,6 @@
+// +build !openbsd
+// +build !windows
+
 package fuse
 
 import (
diff --git a/fuse/snapshot.go b/fuse/snapshot.go
index 99f84e806..80476cc78 100644
--- a/fuse/snapshot.go
+++ b/fuse/snapshot.go
@@ -1,3 +1,6 @@
+// +build !openbsd
+// +build !windows
+
 package fuse
 
 import (
diff --git a/node_test.go b/node_test.go
index 5bdf284bb..f02f0e948 100644
--- a/node_test.go
+++ b/node_test.go
@@ -109,7 +109,7 @@ func TestNodeRestoreAt(t *testing.T) {
 
 	defer func() {
 		if TestCleanup {
-			OK(t, os.RemoveAll(tempdir))
+			RemoveAll(t, tempdir)
 		} else {
 			t.Logf("leaving tempdir at %v", tempdir)
 		}
diff --git a/test/helpers.go b/test/helpers.go
index 504b582ca..1b09b7a0e 100644
--- a/test/helpers.go
+++ b/test/helpers.go
@@ -59,6 +59,7 @@ func Equals(tb testing.TB, exp, act interface{}) {
 	}
 }
 
+// ParseID parses s as a backend.ID and panics if that fails.
 func ParseID(s string) backend.ID {
 	id, err := backend.ParseID(s)
 	if err != nil {
@@ -88,19 +89,18 @@ func RandomReader(seed, size int) *bytes.Reader {
 
 // SetupTarTestFixture extracts the tarFile to outputDir.
 func SetupTarTestFixture(t testing.TB, outputDir, tarFile string) {
-	err := System("sh", "-c", `(cd "$1" && tar xzf - ) < "$2"`,
-		"sh", outputDir, tarFile)
+	f, err := os.Open(tarFile)
+	defer f.Close()
 	OK(t, err)
-}
 
-// System runs the command and returns the exit code. Output is passed on to
-// stdout/stderr.
-func System(command string, args ...string) error {
-	cmd := exec.Command(command, args...)
+	cmd := exec.Command("tar", "xzf", "-")
+	cmd.Dir = outputDir
+
+	cmd.Stdin = f
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
 
-	return cmd.Run()
+	OK(t, cmd.Run())
 }
 
 // WithTestEnvironment creates a test environment, extracts the repository
@@ -124,7 +124,7 @@ func WithTestEnvironment(t testing.TB, repoFixture string, f func(repodir string
 		return
 	}
 
-	OK(t, os.RemoveAll(tempdir))
+	RemoveAll(t, tempdir)
 }
 
 // OpenLocalRepo opens the local repository located at dir.
@@ -138,3 +138,31 @@ func OpenLocalRepo(t testing.TB, dir string) *repository.Repository {
 
 	return repo
 }
+
+func isFile(fi os.FileInfo) bool {
+	return fi.Mode()&(os.ModeType|os.ModeCharDevice) == 0
+}
+
+// ResetReadOnly recursively resets the read-only flag recursively for dir.
+// This is mainly used for tests on Windows, which is unable to delete a file
+// set read-only.
+func ResetReadOnly(t testing.TB, dir string) {
+	OK(t, filepath.Walk(dir, func(path string, fi os.FileInfo, err error) error {
+		if fi.IsDir() {
+			return os.Chmod(path, 0777)
+		}
+
+		if isFile(fi) {
+			return os.Chmod(path, 0666)
+		}
+
+		return nil
+	}))
+}
+
+// RemoveAll recursively resets the read-only flag of all files and dirs and
+// afterwards uses os.RemoveAll() to remove the path.
+func RemoveAll(t testing.TB, path string) {
+	ResetReadOnly(t, path)
+	OK(t, os.RemoveAll(path))
+}
diff --git a/tree_test.go b/tree_test.go
index 2d9cb7b7e..725e80b14 100644
--- a/tree_test.go
+++ b/tree_test.go
@@ -50,7 +50,7 @@ func TestTree(t *testing.T) {
 	dir := createTempDir(t)
 	defer func() {
 		if TestCleanup {
-			OK(t, os.RemoveAll(dir))
+			RemoveAll(t, dir)
 		}
 	}()
 }