diff --git a/cmd/skopeo/inspect.go b/cmd/skopeo/inspect.go
index 0faec960..6b7035fb 100644
--- a/cmd/skopeo/inspect.go
+++ b/cmd/skopeo/inspect.go
@@ -23,8 +23,7 @@ var inspectCmd = cli.Command{
 			logrus.Fatal(err)
 		}
 		if c.Bool("raw") {
-			// TODO(runcom): hardcoded schema 2 version 1
-			b, err := img.RawManifest("2-1")
+			b, err := img.GetManifest()
 			if err != nil {
 				logrus.Fatal(err)
 			}
diff --git a/docker/docker_image.go b/docker/docker_image.go
index a2068dfb..ef99c1cc 100644
--- a/docker/docker_image.go
+++ b/docker/docker_image.go
@@ -19,9 +19,10 @@ var (
 )
 
 type dockerImage struct {
-	src         *dockerImageSource
-	digest      string
-	rawManifest []byte
+	src              *dockerImageSource
+	digest           string
+	rawManifest      []byte
+	cachedSignatures [][]byte // Private cache for GetSignatures; nil if not yet known.
 }
 
 // NewDockerImage returns a new Image interface type after setting up
@@ -34,14 +35,26 @@ func NewDockerImage(img, certPath string, tlsVerify bool) (types.Image, error) {
 	return &dockerImage{src: s}, nil
 }
 
-func (i *dockerImage) RawManifest(version string) ([]byte, error) {
-	// TODO(runcom): unused version param for now, default to docker v2-1
+// GetManifest is like ImageSource.GetManifest, but the result is cached; it is OK to call this however often you need.
+func (i *dockerImage) GetManifest() ([]byte, error) {
 	if err := i.retrieveRawManifest(); err != nil {
 		return nil, err
 	}
 	return i.rawManifest, nil
 }
 
+// GetSignatures is like ImageSource.GetSignatures, but the result is cached; it is OK to call this however often you need.
+func (i *dockerImage) GetSignatures() ([][]byte, error) {
+	if i.cachedSignatures == nil {
+		sigs, err := i.src.GetSignatures()
+		if err != nil {
+			return nil, err
+		}
+		i.cachedSignatures = sigs
+	}
+	return i.cachedSignatures, nil
+}
+
 func (i *dockerImage) Manifest() (types.ImageManifest, error) {
 	// TODO(runcom): unused version param for now, default to docker v2-1
 	m, err := i.getSchema1Manifest()
diff --git a/types/types.go b/types/types.go
index 2acec587..97699743 100644
--- a/types/types.go
+++ b/types/types.go
@@ -47,9 +47,12 @@ type ImageDestination interface {
 // Image is a Docker image in a repository.
 type Image interface {
 	// ref to repository?
+	// GetManifest is like ImageSource.GetManifest, but the result is cached; it is OK to call this however often you need.
+	GetManifest() ([]byte, error)
+	// GetSignatures is like ImageSource.GetSignatures, but the result is cached; it is OK to call this however often you need.
+	GetSignatures() ([][]byte, error)
 	Layers(layers ...string) error // configure download directory? Call it DownloadLayers?
 	Manifest() (ImageManifest, error)
-	RawManifest(version string) ([]byte, error)
 	DockerTar() ([]byte, error) // ??? also, configure output directory
 }