diff --git a/send.go b/send.go
index 5038e9e..0f324bb 100644
--- a/send.go
+++ b/send.go
@@ -77,7 +77,7 @@ func Send(w io.Writer, parent string, subvols ...string) error {
 			if err != nil {
 				return fmt.Errorf("cannot find subvolume %s: %v", rel, err)
 			}
-			rootID = si.RootID
+			rootID = objectID(si.RootID)
 			parentID, err = findGoodParent(mfs.f, rootID, cloneSrc)
 			if err != nil {
 				return fmt.Errorf("cannot find good parent for %v: %v", rel, err)
@@ -205,8 +205,8 @@ func findGoodParent(mnt *os.File, rootID objectID, cloneSrc []objectID) (objectI
 		return 0, fmt.Errorf("get parent failed: %v", err)
 	}
 	for _, id := range cloneSrc {
-		if id == parent.RootID {
-			return parent.RootID, nil
+		if id == objectID(parent.RootID) {
+			return objectID(parent.RootID), nil
 		}
 	}
 	var (
@@ -236,10 +236,10 @@ func findGoodParent(mnt *os.File, rootID objectID, cloneSrc []objectID) (objectI
 		}
 	}
 	if bestParent != nil {
-		return bestParent.RootID, nil
+		return objectID(bestParent.RootID), nil
 	}
 	if !parent.ParentUUID.IsZero() {
-		return findGoodParent(mnt, parent.RootID, cloneSrc)
+		return findGoodParent(mnt, objectID(parent.RootID), cloneSrc)
 	}
 	return 0, ErrNotFound
 }
diff --git a/subvolume.go b/subvolume.go
index 2e52886..0d2d808 100644
--- a/subvolume.go
+++ b/subvolume.go
@@ -204,7 +204,7 @@ func listSubVolumes(f *os.File, filter func(SubvolInfo) bool) (map[objectID]Subv
 			//	m[obj.ObjectID] = o
 			case rootItemKey:
 				o := m[obj.ObjectID]
-				o.RootID = obj.ObjectID
+				o.RootID = uint64(obj.ObjectID)
 				robj := asRootItem(obj.Data).Decode()
 				o.fillFromItem(&robj)
 				m[obj.ObjectID] = o
@@ -251,7 +251,7 @@ func listSubVolumes(f *os.File, filter func(SubvolInfo) bool) (map[objectID]Subv
 }
 
 type SubvolInfo struct {
-	RootID objectID
+	RootID uint64
 
 	UUID         UUID
 	ParentUUID   UUID
@@ -368,12 +368,12 @@ func subvolSearchByRootID(mnt *os.File, rootID objectID, path string) (*SubvolIn
 		return nil, err
 	}
 	info := &SubvolInfo{
-		RootID: rootID,
+		RootID: uint64(rootID),
 		Path:   path,
 	}
 	info.fillFromItem(robj)
 	if path == "" {
-		info.Path, err = subvolidResolve(mnt, info.RootID)
+		info.Path, err = subvolidResolve(mnt, objectID(info.RootID))
 	}
 	return info, err
 }