diff --git a/image/config.go b/image/config.go
index d28b1bc..71d98a7 100644
--- a/image/config.go
+++ b/image/config.go
@@ -31,10 +31,8 @@ import (
 	"github.com/pkg/errors"
 )
 
-type config v1.Image
-
-func findConfig(w walker, d *v1.Descriptor) (*config, error) {
-	var c config
+func findConfig(w walker, d *v1.Descriptor) (*v1.Image, error) {
+	var c v1.Image
 	cpath := filepath.Join("blobs", string(d.Digest.Algorithm()), d.Digest.Hex())
 
 	switch err := w.walk(func(path string, info os.FileInfo, r io.Reader) error {
@@ -65,7 +63,7 @@ func findConfig(w walker, d *v1.Descriptor) (*config, error) {
 	}
 }
 
-func (c *config) runtimeSpec(rootfs string) (*specs.Spec, error) {
+func runtimeSpec(c *v1.Image, rootfs string) (*specs.Spec, error) {
 	if c.OS != "linux" {
 		return nil, fmt.Errorf("%s: unsupported OS", c.OS)
 	}
diff --git a/image/image.go b/image/image.go
index e5c0fe1..e840a39 100644
--- a/image/image.go
+++ b/image/image.go
@@ -105,7 +105,7 @@ func validate(w walker, refs []string, out *log.Logger) error {
 				return err
 			}
 
-			if err := m.validate(w); err != nil {
+			if err := validateManifest(m, w); err != nil {
 				return err
 			}
 		}
@@ -131,7 +131,7 @@ func validate(w walker, refs []string, out *log.Logger) error {
 					return err
 				}
 
-				if err := m.validate(w); err != nil {
+				if err := validateManifest(m, w); err != nil {
 					return err
 				}
 			}
@@ -198,11 +198,11 @@ func unpack(w walker, dest, refName, platform string) error {
 			return err
 		}
 
-		if err := m.validate(w); err != nil {
+		if err := validateManifest(m, w); err != nil {
 			return err
 		}
 
-		return m.unpack(w, dest)
+		return unpackManifest(m, w, dest)
 	}
 
 	if ref.MediaType == validRefMediaTypes[1] {
@@ -221,7 +221,7 @@ func unpack(w walker, dest, refName, platform string) error {
 		}
 
 		for _, m := range manifests {
-			return m.unpack(w, dest)
+			return unpackManifest(m, w, dest)
 		}
 	}
 
@@ -281,7 +281,7 @@ func createRuntimeBundle(w walker, dest, refName, rootfs, platform string) error
 			return err
 		}
 
-		if err := m.validate(w); err != nil {
+		if err := validateManifest(m, w); err != nil {
 			return err
 		}
 
@@ -311,7 +311,7 @@ func createRuntimeBundle(w walker, dest, refName, rootfs, platform string) error
 	return nil
 }
 
-func createBundle(w walker, m *manifest, dest, rootfs string) (retErr error) {
+func createBundle(w walker, m *v1.Manifest, dest, rootfs string) (retErr error) {
 	c, err := findConfig(w, &m.Config)
 	if err != nil {
 		return err
@@ -334,11 +334,11 @@ func createBundle(w walker, m *manifest, dest, rootfs string) (retErr error) {
 		}
 	}
 
-	if err = m.unpack(w, filepath.Join(dest, rootfs)); err != nil {
+	if err = unpackManifest(m, w, filepath.Join(dest, rootfs)); err != nil {
 		return err
 	}
 
-	spec, err := c.runtimeSpec(rootfs)
+	spec, err := runtimeSpec(c, rootfs)
 	if err != nil {
 		return err
 	}
@@ -353,8 +353,8 @@ func createBundle(w walker, m *manifest, dest, rootfs string) (retErr error) {
 }
 
 // filertManifest returns a filtered list of manifests
-func filterManifest(w walker, Manifests []v1.Descriptor, platform string) ([]*manifest, error) {
-	var manifests []*manifest
+func filterManifest(w walker, Manifests []v1.Descriptor, platform string) ([]*v1.Manifest, error) {
+	var manifests []*v1.Manifest
 
 	argsParts := strings.Split(platform, ":")
 	if len(argsParts) != 2 {
@@ -372,7 +372,7 @@ func filterManifest(w walker, Manifests []v1.Descriptor, platform string) ([]*ma
 			return manifests, err
 		}
 
-		if err := m.validate(w); err != nil {
+		if err := validateManifest(m, w); err != nil {
 			return manifests, err
 		}
 		if strings.EqualFold(manifest.Platform.OS, argsParts[0]) && strings.EqualFold(manifest.Platform.Architecture, argsParts[1]) {
diff --git a/image/manifest.go b/image/manifest.go
index 2678c7f..833be7b 100644
--- a/image/manifest.go
+++ b/image/manifest.go
@@ -35,13 +35,8 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-type manifest struct {
-	Config v1.Descriptor   `json:"config"`
-	Layers []v1.Descriptor `json:"layers"`
-}
-
-func findManifest(w walker, d *v1.Descriptor) (*manifest, error) {
-	var m manifest
+func findManifest(w walker, d *v1.Descriptor) (*v1.Manifest, error) {
+	var m v1.Manifest
 	mpath := filepath.Join("blobs", string(d.Digest.Algorithm()), d.Digest.Hex())
 
 	switch err := w.walk(func(path string, info os.FileInfo, r io.Reader) error {
@@ -73,7 +68,7 @@ func findManifest(w walker, d *v1.Descriptor) (*manifest, error) {
 	}
 }
 
-func (m *manifest) validate(w walker) error {
+func validateManifest(m *v1.Manifest, w walker) error {
 	if err := validateDescriptor(&m.Config, w, []string{v1.MediaTypeImageConfig}); err != nil {
 		return errors.Wrap(err, "config validation failed")
 	}
@@ -94,7 +89,7 @@ func (m *manifest) validate(w walker) error {
 	return nil
 }
 
-func (m *manifest) unpack(w walker, dest string) (retErr error) {
+func unpackManifest(m *v1.Manifest, w walker, dest string) (retErr error) {
 	// error out if the dest directory is not empty
 	s, err := ioutil.ReadDir(dest)
 	if err != nil && !os.IsNotExist(err) { // We'll create the dir later
diff --git a/image/manifest_test.go b/image/manifest_test.go
index bb15870..bd79dce 100644
--- a/image/manifest_test.go
+++ b/image/manifest_test.go
@@ -141,7 +141,7 @@ func testUnpackLayer(t *testing.T, compression string, invalid bool) {
 		mediatype += "+" + compression
 	}
 
-	testManifest := manifest{
+	testManifest := v1.Manifest{
 		Layers: []v1.Descriptor{
 			{
 				MediaType: mediatype,
@@ -149,7 +149,7 @@ func testUnpackLayer(t *testing.T, compression string, invalid bool) {
 			},
 		},
 	}
-	err = testManifest.unpack(newPathWalker(tmp1), filepath.Join(tmp1, "rootfs"))
+	err = unpackManifest(&testManifest, newPathWalker(tmp1), filepath.Join(tmp1, "rootfs"))
 	if err != nil {
 		t.Fatal(errors.Wrapf(err, "%q / %s", blobPath, compression))
 	}
@@ -212,7 +212,7 @@ func TestUnpackLayerRemovePartiallyUnpackedFile(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	testManifest := manifest{
+	testManifest := v1.Manifest{
 		Layers: []v1.Descriptor{
 			{
 				MediaType: "application/vnd.oci.image.layer.v1.tar+gzip",
@@ -220,7 +220,7 @@ func TestUnpackLayerRemovePartiallyUnpackedFile(t *testing.T) {
 			},
 		},
 	}
-	err = testManifest.unpack(newPathWalker(tmp1), filepath.Join(tmp1, "rootfs"))
+	err = unpackManifest(&testManifest, newPathWalker(tmp1), filepath.Join(tmp1, "rootfs"))
 	if err != nil && !strings.Contains(err.Error(), "duplicate entry for") {
 		t.Fatal(err)
 	}