diff --git a/cache/manager.go b/cache/manager.go
index 2689804c..0fb0103e 100644
--- a/cache/manager.go
+++ b/cache/manager.go
@@ -106,7 +106,7 @@ func (cm *cacheManager) GetByBlob(ctx context.Context, desc ocispec.Descriptor,
 	blobChainID := imagespecidentity.ChainID([]digest.Digest{desc.Digest, diffID})
 
 	descHandlers := descHandlersOf(opts...)
-	if descHandlers == nil || descHandlers[desc.Digest] == nil {
+	if desc.Digest != "" && (descHandlers == nil || descHandlers[desc.Digest] == nil) {
 		if _, err := cm.ContentStore.Info(ctx, desc.Digest); errors.Is(err, errdefs.ErrNotFound) {
 			return nil, NeedsRemoteProvidersError([]digest.Digest{desc.Digest})
 		} else if err != nil {
diff --git a/cache/refs.go b/cache/refs.go
index bbe95adb..2ddac6d1 100644
--- a/cache/refs.go
+++ b/cache/refs.go
@@ -147,7 +147,12 @@ func (cr *cacheRecord) isLazy(ctx context.Context) (bool, error) {
 	if !getBlobOnly(cr.md) {
 		return false, nil
 	}
-	_, err := cr.cm.ContentStore.Info(ctx, digest.Digest(getBlob(cr.md)))
+	dgst := getBlob(cr.md)
+	// special case for moby where there is no compressed blob (empty digest)
+	if dgst == "" {
+		return false, nil
+	}
+	_, err := cr.cm.ContentStore.Info(ctx, digest.Digest(dgst))
 	if errors.Is(err, errdefs.ErrNotFound) {
 		return true, nil
 	}
@@ -457,6 +462,10 @@ func (sr *immutableRef) extract(ctx context.Context, dhs DescHandlers, s session
 			return nil, nil
 		}
 
+		if sr.cm.Applier == nil {
+			return nil, errors.New("extract requires an applier")
+		}
+
 		eg, egctx := errgroup.WithContext(ctx)
 
 		parentID := ""