diff --git a/storage/storage_dest.go b/storage/storage_dest.go
index 8a85a63916..eb92b036d7 100644
--- a/storage/storage_dest.go
+++ b/storage/storage_dest.go
@@ -806,45 +806,48 @@ func (s *storageImageDestination) createNewLayer(index int, layerDigest digest.D
 		return layer, nil
 	}
 
-	s.lock.Lock()
-	diffID, ok := s.lockProtected.blobDiffIDs[layerDigest]
-	s.lock.Unlock()
-	if !ok {
-		return nil, fmt.Errorf("failed to find diffID for layer: %q", layerDigest)
-	}
-	optionalDiffID := diffID // FIXME
-
 	// Check if we previously cached a file with that blob's contents.  If we didn't,
 	// then we need to read the desired contents from a layer.
 	var trustedUncompressedDigest, trustedOriginalDigest digest.Digest // For storage.LayerOptions
 	s.lock.Lock()
+	tocDigest := s.lockProtected.indexToTOCDigest[index]       // "" if not set
+	optionalDiffID := s.lockProtected.blobDiffIDs[layerDigest] // "" if not set
 	filename, gotFilename := s.lockProtected.filenames[layerDigest]
-	_, layerIdentifiedByTOC := s.lockProtected.indexToTOCDigest[index]
 	s.lock.Unlock()
-	if gotFilename && !layerIdentifiedByTOC {
-		// If layerIdentifiedByTOC, if we now happen to find a layerDigest match, the newLayerID has already been computed as TOC-based,
+	if gotFilename && tocDigest == "" {
+		// If tocDigest != "", if we now happen to find a layerDigest match, the newLayerID has already been computed as TOC-based,
 		// and we don't know the relationship of the layerDigest and TOC digest.
 		// We could recompute newLayerID to be DiffID-based and use the file, but such a within-image layer
 		// reuse is expected to be pretty rare; instead, ignore the unexpected file match and proceed to the
 		// originally-planned TOC match.
 
-		// Because !layerIdentifiedByTOC, optionaldiffID must have been set; and even if it weren’t, PutLayer will recompute the digest from the stream.
+		// Because tocDigest == "", optionaldiffID must have been set; and even if it weren’t, PutLayer will recompute the digest from the stream.
 		trustedUncompressedDigest = optionalDiffID
 		trustedOriginalDigest = layerDigest // The code setting .filenames[layerDigest] is responsible for the contents matching.
 	} else {
-		// Try to find the layer with contents matching that blobsum.
+		// Try to find the layer with contents matching the data we use.
 		var layer *storage.Layer // = nil
-		layers, err2 := s.imageRef.transport.store.LayersByUncompressedDigest(diffID)
-		if err2 == nil && len(layers) > 0 {
-			layer = &layers[0]
+		if tocDigest != "" {
+			layers, err2 := s.imageRef.transport.store.LayersByTOCDigest(tocDigest)
+			if err2 == nil && len(layers) > 0 {
+				layer = &layers[0]
+			} else {
+				return nil, fmt.Errorf("locating layer for TOC digest %q: %w", tocDigest, err2)
+			}
 		} else {
-			layers, err2 = s.imageRef.transport.store.LayersByCompressedDigest(layerDigest)
+			// Because tocDigest == "", optionaldiffID must have been set
+			layers, err2 := s.imageRef.transport.store.LayersByUncompressedDigest(optionalDiffID)
 			if err2 == nil && len(layers) > 0 {
 				layer = &layers[0]
+			} else {
+				layers, err2 = s.imageRef.transport.store.LayersByCompressedDigest(layerDigest)
+				if err2 == nil && len(layers) > 0 {
+					layer = &layers[0]
+				}
+			}
+			if layer == nil {
+				return nil, fmt.Errorf("locating layer for blob %q: %w", layerDigest, err2)
 			}
-		}
-		if layer == nil {
-			return nil, fmt.Errorf("locating layer for blob %q: %w", layerDigest, err2)
 		}
 		// Read the layer's contents.
 		noCompression := archive.Uncompressed
@@ -876,7 +879,7 @@ func (s *storageImageDestination) createNewLayer(index int, layerDigest digest.D
 		}
 
 		// FIXME CLEAN THIS UP
-		if !layerIdentifiedByTOC {
+		if tocDigest == "" {
 			// If we found the layer using LayersByUncompressedDigest(diffID):
 			// - trustedUncompressedDigest = diffID by definition, and diffID is set
 			// - trustedOriginalDigest = layerDigest is trusted by construction of blobDiffIDs (probably from BlobInfoCache, which is trusted)