diff --git a/osfs/os_test.go b/osfs/os_test.go
index 2bb5388..767dc74 100644
--- a/osfs/os_test.go
+++ b/osfs/os_test.go
@@ -20,7 +20,7 @@ type OSSuite struct {
 var _ = Suite(&OSSuite{})
 
 func (s *OSSuite) SetUpTest(c *C) {
-	s.path, _ = ioutil.TempDir(os.TempDir(), "go-git-os-fs-test")
+	s.path, _ = ioutil.TempDir(os.TempDir(), "go-billy-osfs-test")
 	s.FilesystemSuite.FS = New(s.path)
 }
 
diff --git a/subdir/file.go b/subdir/file.go
index 34fbb19..d2e4f27 100644
--- a/subdir/file.go
+++ b/subdir/file.go
@@ -3,7 +3,6 @@ package subdir
 import (
 	"io"
 	"path/filepath"
-	"strings"
 
 	"gopkg.in/src-d/go-billy.v2"
 )
@@ -14,9 +13,12 @@ type file struct {
 	f billy.File
 }
 
-func newFile(f billy.File, filename string) billy.File {
+func newFile(fs billy.Filesystem, f billy.File, filename string) billy.File {
+	filename = fs.Join(fs.Base(), filename)
+	filename, _ = filepath.Rel(fs.Base(), filename)
+
 	return &file{
-		BaseFile: billy.BaseFile{BaseFilename: resolve(filename)},
+		BaseFile: billy.BaseFile{BaseFilename: filename},
 		f:        f,
 	}
 }
@@ -46,14 +48,3 @@ func (f *file) Close() error {
 	defer func() { f.Closed = true }()
 	return f.f.Close()
 }
-
-func resolve(path string) string {
-	rp := filepath.Clean(path)
-	if rp == "/" {
-		rp = "."
-	} else if strings.HasPrefix(rp, "/") {
-		rp = rp[1:]
-	}
-
-	return rp
-}
diff --git a/subdir/subdir.go b/subdir/subdir.go
index d52cb8d..5722292 100644
--- a/subdir/subdir.go
+++ b/subdir/subdir.go
@@ -33,7 +33,7 @@ func (s *subdirFs) Create(filename string) (billy.File, error) {
 		return nil, err
 	}
 
-	return newFile(f, filename), nil
+	return newFile(s, f, filename), nil
 }
 
 func (s *subdirFs) Open(filename string) (billy.File, error) {
@@ -42,7 +42,7 @@ func (s *subdirFs) Open(filename string) (billy.File, error) {
 		return nil, err
 	}
 
-	return newFile(f, filename), nil
+	return newFile(s, f, filename), nil
 }
 
 func (s *subdirFs) OpenFile(filename string, flag int, mode os.FileMode) (
@@ -53,7 +53,7 @@ func (s *subdirFs) OpenFile(filename string, flag int, mode os.FileMode) (
 		return nil, err
 	}
 
-	return newFile(f, filename), nil
+	return newFile(s, f, filename), nil
 }
 
 func (s *subdirFs) TempFile(dir, prefix string) (billy.File, error) {
@@ -62,7 +62,7 @@ func (s *subdirFs) TempFile(dir, prefix string) (billy.File, error) {
 		return nil, err
 	}
 
-	return newFile(f, s.Join(dir, filepath.Base(f.Filename()))), nil
+	return newFile(s, f, s.Join(dir, filepath.Base(f.Filename()))), nil
 }
 
 func (s *subdirFs) Rename(from, to string) error {
@@ -79,8 +79,13 @@ func (s *subdirFs) MkdirAll(filename string, perm os.FileMode) error {
 }
 
 func (s *subdirFs) Stat(filename string) (billy.FileInfo, error) {
-	filename = removeLeadingSlash(filename)
-	fi, err := s.underlying.Stat(s.underlyingPath(filename))
+	fullpath := s.underlyingPath(filename)
+	fi, err := s.underlying.Stat(fullpath)
+	if err != nil {
+		return nil, err
+	}
+
+	filename, err = filepath.Rel(s.Base(), fullpath)
 	if err != nil {
 		return nil, err
 	}
@@ -107,17 +112,9 @@ func (s *subdirFs) Join(elem ...string) string {
 }
 
 func (s *subdirFs) Dir(path string) billy.Filesystem {
-	return New(s, removeLeadingSlash(path))
+	return New(s.underlying, s.underlyingPath(path))
 }
 
 func (s *subdirFs) Base() string {
 	return s.base
 }
-
-func removeLeadingSlash(path string) string {
-	if strings.HasPrefix(path, "/") {
-		return path[1:]
-	}
-
-	return path
-}
diff --git a/subdir/suite_test.go b/subdir/subdir_test.go
similarity index 83%
rename from subdir/suite_test.go
rename to subdir/subdir_test.go
index e2b2214..197913b 100644
--- a/subdir/suite_test.go
+++ b/subdir/subdir_test.go
@@ -23,9 +23,10 @@ type FilesystemSuite struct {
 var _ = Suite(&FilesystemSuite{})
 
 func (s *FilesystemSuite) SetUpTest(c *C) {
-	s.path, _ = ioutil.TempDir(stdos.TempDir(), "go-git-fs-test")
-	osFs := osfs.New(s.path)
-	s.cfs = New(osFs, "test-subdir")
+	s.path, _ = ioutil.TempDir(stdos.TempDir(), "go-billy-subdirfs-test")
+	fs := osfs.New(s.path)
+
+	s.cfs = New(fs, "test-subdir")
 	s.FilesystemSuite.FS = s.cfs
 }
 
diff --git a/test/fs_suite.go b/test/fs_suite.go
index 16ff18c..637ab33 100644
--- a/test/fs_suite.go
+++ b/test/fs_suite.go
@@ -6,6 +6,7 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 
@@ -23,6 +24,7 @@ func (s *FilesystemSuite) TestCreate(c *C) {
 	f, err := s.FS.Create("foo")
 	c.Assert(err, IsNil)
 	c.Assert(f.Filename(), Equals, "foo")
+	c.Assert(f.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestOpen(c *C) {
@@ -34,6 +36,7 @@ func (s *FilesystemSuite) TestOpen(c *C) {
 	f, err = s.FS.Open("foo")
 	c.Assert(err, IsNil)
 	c.Assert(f.Filename(), Equals, "foo")
+	c.Assert(f.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestOpenNotExists(c *C) {
@@ -54,13 +57,15 @@ func (s *FilesystemSuite) TestCreateDir(c *C) {
 func (s *FilesystemSuite) TestCreateDepth(c *C) {
 	f, err := s.FS.Create("bar/foo")
 	c.Assert(err, IsNil)
-	c.Assert(f.Filename(), Equals, "bar/foo")
+	c.Assert(f.Filename(), Equals, s.FS.Join("bar", "foo"))
+	c.Assert(f.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestCreateDepthAbsolute(c *C) {
 	f, err := s.FS.Create("/bar/foo")
 	c.Assert(err, IsNil)
-	c.Assert(f.Filename(), Equals, "bar/foo")
+	c.Assert(f.Filename(), Equals, s.FS.Join("bar", "foo"))
+	c.Assert(f.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestCreateOverwrite(c *C) {
@@ -82,6 +87,7 @@ func (s *FilesystemSuite) TestCreateOverwrite(c *C) {
 	wrote, err := ioutil.ReadAll(f)
 	c.Assert(err, IsNil)
 	c.Assert(string(wrote), DeepEquals, "foo2")
+	c.Assert(f.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestCreateClose(c *C) {
@@ -199,13 +205,13 @@ func (s *FilesystemSuite) TestOpenFileReadWrite(c *C) {
 }
 
 func (s *FilesystemSuite) TestOpenFileWithModes(c *C) {
-	f, err := s.FS.OpenFile("foo", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0755)
+	f, err := s.FS.OpenFile("foo", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, customMode)
 	c.Assert(err, IsNil)
 	c.Assert(f.Close(), IsNil)
 
 	fi, err := s.FS.Stat("foo")
 	c.Assert(err, IsNil)
-	c.Assert(fi.Mode(), Equals, os.FileMode(0755))
+	c.Assert(fi.Mode(), Equals, os.FileMode(customMode))
 }
 
 func (s *FilesystemSuite) testWriteClose(c *C, f File, content string) {
@@ -281,6 +287,8 @@ func (s *FilesystemSuite) TestFileNonRead(c *C) {
 
 	_, err = ioutil.ReadAll(f)
 	c.Assert(err, NotNil)
+
+	c.Assert(f.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestFileSeekstart(c *C) {
@@ -478,11 +486,14 @@ func (s *FilesystemSuite) TestDirStat(c *C) {
 }
 
 func (s *FilesystemSuite) TestCreateInDir(c *C) {
-	dir := s.FS.Dir("foo")
-	f, err := dir.Create("bar")
+	f, err := s.FS.Dir("foo").Create("bar")
 	c.Assert(err, IsNil)
 	c.Assert(f.Close(), IsNil)
 	c.Assert(f.Filename(), Equals, "bar")
+
+	f, err = s.FS.Open("foo/bar")
+	c.Assert(f.Filename(), Equals, s.FS.Join("foo", "bar"))
+	c.Assert(f.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestRename(c *C) {
@@ -531,6 +542,7 @@ func (s *FilesystemSuite) TestRenameDir(c *C) {
 func (s *FilesystemSuite) TestTempFile(c *C) {
 	f, err := s.FS.TempFile("", "bar")
 	c.Assert(err, IsNil)
+	c.Assert(f.Close(), IsNil)
 
 	c.Assert(strings.HasPrefix(f.Filename(), "bar"), Equals, true)
 }
@@ -538,12 +550,16 @@ func (s *FilesystemSuite) TestTempFile(c *C) {
 func (s *FilesystemSuite) TestTempFileWithPath(c *C) {
 	f, err := s.FS.TempFile("foo", "bar")
 	c.Assert(err, IsNil)
+	c.Assert(f.Close(), IsNil)
+
 	c.Assert(strings.HasPrefix(f.Filename(), s.FS.Join("foo", "bar")), Equals, true)
 }
 
 func (s *FilesystemSuite) TestTempFileFullWithPath(c *C) {
 	f, err := s.FS.TempFile("/foo", "bar")
 	c.Assert(err, IsNil)
+	c.Assert(f.Close(), IsNil)
+
 	c.Assert(strings.HasPrefix(f.Filename(), s.FS.Join("foo", "bar")), Equals, true)
 }
 
@@ -558,6 +574,8 @@ func (s *FilesystemSuite) TestOpenAndWrite(c *C) {
 	n, err := foo.Write([]byte("foo"))
 	c.Assert(err, NotNil)
 	c.Assert(n, Equals, 0)
+
+	c.Assert(foo.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestOpenAndStat(c *C) {
@@ -568,6 +586,7 @@ func (s *FilesystemSuite) TestOpenAndStat(c *C) {
 	c.Assert(foo, NotNil)
 	c.Assert(foo.Filename(), Equals, "foo")
 	c.Assert(err, IsNil)
+	c.Assert(foo.Close(), IsNil)
 
 	stat, err := s.FS.Stat("foo")
 	c.Assert(stat, NotNil)
@@ -611,7 +630,7 @@ func (s *FilesystemSuite) TestRemoveTempFile(c *C) {
 }
 
 func (s *FilesystemSuite) TestJoin(c *C) {
-	c.Assert(s.FS.Join("foo", "bar"), Equals, "foo/bar")
+	c.Assert(s.FS.Join("foo", "bar"), Equals, fmt.Sprintf("foo%cbar", filepath.Separator))
 }
 
 func (s *FilesystemSuite) TestBase(c *C) {
@@ -663,14 +682,14 @@ func (s *FilesystemSuite) TestReadWriteLargeFile(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(n, Equals, size)
 
-	err = f.Close()
-	c.Assert(err, IsNil)
+	c.Assert(f.Close(), IsNil)
 
 	f, err = s.FS.Open("foo")
 	c.Assert(err, IsNil)
 	b, err := ioutil.ReadAll(f)
 	c.Assert(err, IsNil)
 	c.Assert(len(b), Equals, size)
+	c.Assert(f.Close(), IsNil)
 }
 
 func (s *FilesystemSuite) TestRemoveAllNonExistent(c *C) {
@@ -806,4 +825,6 @@ func (s *FilesystemSuite) TestWriteFile(c *C) {
 	wrote, err := ioutil.ReadAll(f)
 	c.Assert(err, IsNil)
 	c.Assert(string(wrote), DeepEquals, "bar")
+
+	c.Assert(f.Close(), IsNil)
 }
diff --git a/test/fs_suite_linux.go b/test/fs_suite_linux.go
new file mode 100644
index 0000000..8f51534
--- /dev/null
+++ b/test/fs_suite_linux.go
@@ -0,0 +1,7 @@
+// +build !windows
+
+package test
+
+import "os"
+
+var customMode os.FileMode = 0755
diff --git a/test/fs_suite_windows.go b/test/fs_suite_windows.go
new file mode 100644
index 0000000..cc289f8
--- /dev/null
+++ b/test/fs_suite_windows.go
@@ -0,0 +1,7 @@
+// +build windows
+
+package test
+
+import "os"
+
+var customMode os.FileMode = 0666