diff --git a/helper/chroot/chroot.go b/helper/chroot/chroot.go
index 71524ec..e3e5a6d 100644
--- a/helper/chroot/chroot.go
+++ b/helper/chroot/chroot.go
@@ -37,7 +37,7 @@ func isCrossBoundaries(path string) bool {
 	path = filepath.ToSlash(path)
 	path = filepath.Clean(path)
 
-	return strings.HasPrefix(path, "..")
+	return strings.HasPrefix(path, ".."+string(filepath.Separator))
 }
 
 func (fs *ChrootHelper) Create(filename string) (billy.File, error) {
diff --git a/helper/chroot/chroot_test.go b/helper/chroot/chroot_test.go
index 43bd6e6..580347a 100644
--- a/helper/chroot/chroot_test.go
+++ b/helper/chroot/chroot_test.go
@@ -37,6 +37,15 @@ func (s *ChrootSuite) TestCreateErrCrossedBoundary(c *C) {
 	c.Assert(err, Equals, billy.ErrCrossedBoundary)
 }
 
+func (s *ChrootSuite) TestLeadingPeriodsPathNotCrossedBoundary(c *C) {
+	m := &test.BasicMock{}
+
+	fs := New(m, "/foo")
+	f, err := fs.Create("..foo")
+	c.Assert(err, IsNil)
+	c.Assert(f.Name(), Equals, "..foo")
+}
+
 func (s *ChrootSuite) TestOpen(c *C) {
 	m := &test.BasicMock{}