diff --git a/manifest/ocischema/builder_test.go b/manifest/ocischema/builder_test.go
index 2e511393..e1fe516c 100644
--- a/manifest/ocischema/builder_test.go
+++ b/manifest/ocischema/builder_test.go
@@ -12,6 +12,7 @@ import (
 
 type mockBlobService struct {
 	descriptors map[digest.Digest]distribution.Descriptor
+	distribution.BlobService
 }
 
 func (bs *mockBlobService) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
@@ -21,14 +22,6 @@ func (bs *mockBlobService) Stat(ctx context.Context, dgst digest.Digest) (distri
 	return distribution.Descriptor{}, distribution.ErrBlobUnknown
 }
 
-func (bs *mockBlobService) Get(ctx context.Context, dgst digest.Digest) ([]byte, error) {
-	panic("not implemented")
-}
-
-func (bs *mockBlobService) Open(ctx context.Context, dgst digest.Digest) (distribution.ReadSeekCloser, error) {
-	panic("not implemented")
-}
-
 func (bs *mockBlobService) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) {
 	d := distribution.Descriptor{
 		Digest:    digest.FromBytes(p),
@@ -39,14 +32,6 @@ func (bs *mockBlobService) Put(ctx context.Context, mediaType string, p []byte)
 	return d, nil
 }
 
-func (bs *mockBlobService) Create(ctx context.Context, options ...distribution.BlobCreateOption) (distribution.BlobWriter, error) {
-	panic("not implemented")
-}
-
-func (bs *mockBlobService) Resume(ctx context.Context, id string) (distribution.BlobWriter, error) {
-	panic("not implemented")
-}
-
 func TestBuilder(t *testing.T) {
 	imgJSON := []byte(`{
     "created": "2015-10-31T22:22:56.015925234Z",
diff --git a/manifest/schema1/config_builder_test.go b/manifest/schema1/config_builder_test.go
index 788332be..688e73eb 100644
--- a/manifest/schema1/config_builder_test.go
+++ b/manifest/schema1/config_builder_test.go
@@ -17,6 +17,7 @@ import (
 
 type mockBlobService struct {
 	descriptors map[digest.Digest]distribution.Descriptor
+	distribution.BlobService
 }
 
 func (bs *mockBlobService) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
@@ -26,14 +27,6 @@ func (bs *mockBlobService) Stat(ctx context.Context, dgst digest.Digest) (distri
 	return distribution.Descriptor{}, distribution.ErrBlobUnknown
 }
 
-func (bs *mockBlobService) Get(ctx context.Context, dgst digest.Digest) ([]byte, error) {
-	panic("not implemented")
-}
-
-func (bs *mockBlobService) Open(ctx context.Context, dgst digest.Digest) (distribution.ReadSeekCloser, error) {
-	panic("not implemented")
-}
-
 func (bs *mockBlobService) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) {
 	d := distribution.Descriptor{
 		Digest:    digest.FromBytes(p),
@@ -44,14 +37,6 @@ func (bs *mockBlobService) Put(ctx context.Context, mediaType string, p []byte)
 	return d, nil
 }
 
-func (bs *mockBlobService) Create(ctx context.Context, options ...distribution.BlobCreateOption) (distribution.BlobWriter, error) {
-	panic("not implemented")
-}
-
-func (bs *mockBlobService) Resume(ctx context.Context, id string) (distribution.BlobWriter, error) {
-	panic("not implemented")
-}
-
 func TestEmptyTar(t *testing.T) {
 	// Confirm that gzippedEmptyTar expands to 1024 NULL bytes.
 	var decompressed [2048]byte
diff --git a/manifest/schema2/builder_test.go b/manifest/schema2/builder_test.go
index 7a039799..81b0ea05 100644
--- a/manifest/schema2/builder_test.go
+++ b/manifest/schema2/builder_test.go
@@ -11,6 +11,7 @@ import (
 
 type mockBlobService struct {
 	descriptors map[digest.Digest]distribution.Descriptor
+	distribution.BlobService
 }
 
 func (bs *mockBlobService) Stat(ctx context.Context, dgst digest.Digest) (distribution.Descriptor, error) {
@@ -20,14 +21,6 @@ func (bs *mockBlobService) Stat(ctx context.Context, dgst digest.Digest) (distri
 	return distribution.Descriptor{}, distribution.ErrBlobUnknown
 }
 
-func (bs *mockBlobService) Get(ctx context.Context, dgst digest.Digest) ([]byte, error) {
-	panic("not implemented")
-}
-
-func (bs *mockBlobService) Open(ctx context.Context, dgst digest.Digest) (distribution.ReadSeekCloser, error) {
-	panic("not implemented")
-}
-
 func (bs *mockBlobService) Put(ctx context.Context, mediaType string, p []byte) (distribution.Descriptor, error) {
 	d := distribution.Descriptor{
 		Digest:    digest.FromBytes(p),
@@ -38,14 +31,6 @@ func (bs *mockBlobService) Put(ctx context.Context, mediaType string, p []byte)
 	return d, nil
 }
 
-func (bs *mockBlobService) Create(ctx context.Context, options ...distribution.BlobCreateOption) (distribution.BlobWriter, error) {
-	panic("not implemented")
-}
-
-func (bs *mockBlobService) Resume(ctx context.Context, id string) (distribution.BlobWriter, error) {
-	panic("not implemented")
-}
-
 func TestBuilder(t *testing.T) {
 	imgJSON := []byte(`{
     "architecture": "amd64",
diff --git a/registry/proxy/proxytagservice_test.go b/registry/proxy/proxytagservice_test.go
index e0f99c0f..61e15852 100644
--- a/registry/proxy/proxytagservice_test.go
+++ b/registry/proxy/proxytagservice_test.go
@@ -13,10 +13,9 @@ import (
 type mockTagStore struct {
 	mapping map[string]distribution.Descriptor
 	sync.Mutex
+	distribution.TagService
 }
 
-var _ distribution.TagService = &mockTagStore{}
-
 func (m *mockTagStore) Get(ctx context.Context, tag string) (distribution.Descriptor, error) {
 	m.Lock()
 	defer m.Unlock()
@@ -58,10 +57,6 @@ func (m *mockTagStore) All(ctx context.Context) ([]string, error) {
 	return tags, nil
 }
 
-func (m *mockTagStore) Lookup(ctx context.Context, digest distribution.Descriptor) ([]string, error) {
-	panic("not implemented")
-}
-
 func testProxyTagService(local, remote map[string]distribution.Descriptor) *proxyTagService {
 	if local == nil {
 		local = make(map[string]distribution.Descriptor)