diff --git a/api/data/tree.go b/api/data/tree.go
index a11095c3..31635303 100644
--- a/api/data/tree.go
+++ b/api/data/tree.go
@@ -27,6 +27,7 @@ type DeleteMarkerInfo struct {
 type ExtendedObjectInfo struct {
 	ObjectInfo  *ObjectInfo
 	NodeVersion *NodeVersion
+	IsLatest    bool
 }
 
 // BaseNodeVersion is minimal node info from tree service.
diff --git a/api/handler/object_list.go b/api/handler/object_list.go
index e59a26d7..947d8db3 100644
--- a/api/handler/object_list.go
+++ b/api/handler/object_list.go
@@ -272,6 +272,10 @@ func encodeListObjectVersionsToResponse(info *layer.ListObjectVersionsInfo, buck
 	}
 
 	for _, ver := range info.Version {
+		versionID := ver.Object.Version()
+		if ver.IsUnversioned {
+			versionID = layer.UnversionedObjectVersionID
+		}
 		res.Version = append(res.Version, ObjectVersionResponse{
 			IsLatest:     ver.IsLatest,
 			Key:          ver.Object.Name,
@@ -281,7 +285,7 @@ func encodeListObjectVersionsToResponse(info *layer.ListObjectVersionsInfo, buck
 				DisplayName: ver.Object.Owner.String(),
 			},
 			Size:      ver.Object.Size,
-			VersionID: ver.Object.Version(), // todo return "null" version for unversioned https://github.com/nspcc-dev/neofs-s3-gw/issues/474
+			VersionID: versionID,
 			ETag:      ver.Object.HashSum,
 		})
 	}
diff --git a/api/handler/object_list_test.go b/api/handler/object_list_test.go
index 7b6a2f8f..d28175a8 100644
--- a/api/handler/object_list_test.go
+++ b/api/handler/object_list_test.go
@@ -1,8 +1,12 @@
 package handler
 
 import (
+	"bytes"
+	"context"
+	"net/http"
 	"testing"
 
+	"github.com/nspcc-dev/neofs-s3-gw/api/layer"
 	"github.com/stretchr/testify/require"
 )
 
@@ -35,3 +39,37 @@ func TestParseContinuationToken(t *testing.T) {
 		require.Equal(t, tokenStr, token)
 	})
 }
+
+func TestListObjectNullVersions(t *testing.T) {
+	ctx := context.Background()
+	hc := prepareHandlerContext(t)
+
+	bktName := "bucket-versioning-enabled"
+	createTestBucket(ctx, t, hc, bktName)
+
+	objName := "object"
+
+	body := bytes.NewReader([]byte("content"))
+	w, r := prepareTestPayloadRequest(bktName, objName, body)
+	hc.Handler().PutObjectHandler(w, r)
+	assertStatus(t, w, http.StatusOK)
+
+	versioning := &VersioningConfiguration{Status: "Enabled"}
+	w, r = prepareTestRequest(t, bktName, objName, versioning)
+	hc.Handler().PutBucketVersioningHandler(w, r)
+	assertStatus(t, w, http.StatusOK)
+
+	body2 := bytes.NewReader([]byte("content2"))
+	w, r = prepareTestPayloadRequest(bktName, objName, body2)
+	hc.Handler().PutObjectHandler(w, r)
+	assertStatus(t, w, http.StatusOK)
+
+	w, r = prepareTestRequest(t, bktName, objName, nil)
+	hc.Handler().ListBucketObjectVersionsHandler(w, r)
+
+	result := &ListObjectsVersionsResponse{}
+	parseTestResponse(t, w, result)
+
+	require.Len(t, result.Version, 2)
+	require.Equal(t, layer.UnversionedObjectVersionID, result.Version[1].VersionID)
+}
diff --git a/api/layer/layer.go b/api/layer/layer.go
index 31f00d94..8722791b 100644
--- a/api/layer/layer.go
+++ b/api/layer/layer.go
@@ -470,14 +470,14 @@ func getRandomOID() (*oid.ID, error) {
 
 // DeleteObject removes all objects with the passed nice name.
 func (n *layer) deleteObject(ctx context.Context, bkt *data.BucketInfo, settings *data.BucketSettings, obj *VersionedObject) *VersionedObject {
-	if len(obj.VersionID) == 0 || obj.VersionID == unversionedObjectVersionID {
+	if len(obj.VersionID) == 0 || obj.VersionID == UnversionedObjectVersionID {
 		randOID, err := getRandomOID()
 		if err != nil {
 			obj.Error = fmt.Errorf("couldn't get random oid: %w", err)
 			return obj
 		}
 
-		obj.DeleteMarkVersion = unversionedObjectVersionID
+		obj.DeleteMarkVersion = UnversionedObjectVersionID
 		newVersion := &data.NodeVersion{
 			BaseNodeVersion: data.BaseNodeVersion{
 				OID: *randOID,
diff --git a/api/layer/object.go b/api/layer/object.go
index 032f9c1c..9aab0903 100644
--- a/api/layer/object.go
+++ b/api/layer/object.go
@@ -277,7 +277,7 @@ func (n *layer) headLastVersionIfNotDeleted(ctx context.Context, bkt *data.Bucke
 func (n *layer) headVersion(ctx context.Context, bkt *data.BucketInfo, p *HeadObjectParams) (*data.ObjectInfo, error) {
 	var err error
 	var foundVersion *data.NodeVersion
-	if p.VersionID == unversionedObjectVersionID {
+	if p.VersionID == UnversionedObjectVersionID {
 		foundVersion, err = n.treeService.GetUnversioned(ctx, &bkt.CID, p.Object)
 		if err != nil {
 			if errors.Is(err, ErrNodeNotFound) {
@@ -572,6 +572,18 @@ func triageObjects(allObjects []*data.ObjectInfo) (prefixes []string, objects []
 	return
 }
 
+func triageExtendedObjects(allObjects []*data.ExtendedObjectInfo) (prefixes []string, objects []*data.ExtendedObjectInfo) {
+	for _, ov := range allObjects {
+		if ov.ObjectInfo.IsDir {
+			prefixes = append(prefixes, ov.ObjectInfo.Name)
+		} else {
+			objects = append(objects, ov)
+		}
+	}
+
+	return
+}
+
 func (n *layer) listAllObjects(ctx context.Context, p ListObjectsParamsCommon) ([]*data.ObjectInfo, error) {
 	var (
 		err        error
diff --git a/api/layer/tagging.go b/api/layer/tagging.go
index 393e7a86..acffc5ec 100644
--- a/api/layer/tagging.go
+++ b/api/layer/tagging.go
@@ -131,7 +131,7 @@ func (n *layer) getNodeVersion(ctx context.Context, objVersion *ObjectVersion) (
 	var err error
 	var version *data.NodeVersion
 
-	if objVersion.VersionID == unversionedObjectVersionID {
+	if objVersion.VersionID == UnversionedObjectVersionID {
 		version, err = n.treeService.GetUnversioned(ctx, &objVersion.BktInfo.CID, objVersion.ObjectName)
 	} else if len(objVersion.VersionID) == 0 {
 		version, err = n.treeService.GetLatestVersion(ctx, &objVersion.BktInfo.CID, objVersion.ObjectName)
diff --git a/api/layer/util.go b/api/layer/util.go
index eaca9965..80e13a53 100644
--- a/api/layer/util.go
+++ b/api/layer/util.go
@@ -37,8 +37,9 @@ type (
 
 	// ObjectVersionInfo stores info about objects versions.
 	ObjectVersionInfo struct {
-		Object   *data.ObjectInfo
-		IsLatest bool
+		Object        *data.ObjectInfo
+		IsLatest      bool
+		IsUnversioned bool
 	}
 
 	// ListObjectVersionsInfo stores info and list of objects versions.
diff --git a/api/layer/versioning.go b/api/layer/versioning.go
index aa016d8c..49503ab3 100644
--- a/api/layer/versioning.go
+++ b/api/layer/versioning.go
@@ -8,12 +8,12 @@ import (
 )
 
 const (
-	unversionedObjectVersionID = "null"
+	UnversionedObjectVersionID = "null"
 )
 
 func (n *layer) ListObjectVersions(ctx context.Context, p *ListObjectVersionsParams) (*ListObjectVersionsInfo, error) {
 	var (
-		allObjects = make([]*data.ObjectInfo, 0, p.MaxKeys)
+		allObjects = make([]*data.ExtendedObjectInfo, 0, p.MaxKeys)
 		res        = &ListObjectVersionsInfo{}
 	)
 
@@ -34,35 +34,37 @@ func (n *layer) ListObjectVersions(ctx context.Context, p *ListObjectVersionsPar
 			return sortedVersions[j].NodeVersion.Timestamp < sortedVersions[i].NodeVersion.Timestamp // sort in reverse order
 		})
 
-		for _, version := range sortedVersions {
-			allObjects = append(allObjects, version.ObjectInfo)
+		for i, version := range sortedVersions {
+			version.IsLatest = i == 0
+			allObjects = append(allObjects, version)
 		}
 	}
 
 	for i, obj := range allObjects {
-		if obj.Name >= p.KeyMarker && obj.Version() >= p.VersionIDMarker {
+		if obj.ObjectInfo.Name >= p.KeyMarker && obj.ObjectInfo.Version() >= p.VersionIDMarker {
 			allObjects = allObjects[i:]
 			break
 		}
 	}
 
-	res.CommonPrefixes, allObjects = triageObjects(allObjects)
+	res.CommonPrefixes, allObjects = triageExtendedObjects(allObjects)
 
 	if len(allObjects) > p.MaxKeys {
 		res.IsTruncated = true
-		res.NextKeyMarker = allObjects[p.MaxKeys].Name
-		res.NextVersionIDMarker = allObjects[p.MaxKeys].Version()
+		res.NextKeyMarker = allObjects[p.MaxKeys].ObjectInfo.Name
+		res.NextVersionIDMarker = allObjects[p.MaxKeys].ObjectInfo.Version()
 
 		allObjects = allObjects[:p.MaxKeys]
-		res.KeyMarker = allObjects[p.MaxKeys-1].Name
-		res.VersionIDMarker = allObjects[p.MaxKeys-1].Version()
+		res.KeyMarker = allObjects[p.MaxKeys-1].ObjectInfo.Name
+		res.VersionIDMarker = allObjects[p.MaxKeys-1].ObjectInfo.Version()
 	}
 
 	objects := make([]*ObjectVersionInfo, len(allObjects))
 	for i, obj := range allObjects {
-		objects[i] = &ObjectVersionInfo{Object: obj}
-		if i == 0 || allObjects[i-1].Name != obj.Name {
-			objects[i].IsLatest = true
+		objects[i] = &ObjectVersionInfo{
+			Object:        obj.ObjectInfo,
+			IsUnversioned: obj.NodeVersion.IsUnversioned,
+			IsLatest:      obj.IsLatest,
 		}
 	}
 
diff --git a/api/layer/versioning_test.go b/api/layer/versioning_test.go
index dd510abc..de61a903 100644
--- a/api/layer/versioning_test.go
+++ b/api/layer/versioning_test.go
@@ -250,7 +250,7 @@ func TestGetUnversioned(t *testing.T) {
 	})
 	require.NoError(t, err)
 
-	resInfo, buffer := tc.getObject(tc.obj, unversionedObjectVersionID, false)
+	resInfo, buffer := tc.getObject(tc.obj, UnversionedObjectVersionID, false)
 	require.Equal(t, objContent, buffer)
 	require.Equal(t, objInfo.Version(), resInfo.Version())
 }
@@ -278,7 +278,8 @@ func TestVersioningDeleteSpecificObjectVersion(t *testing.T) {
 	tc.deleteObject(tc.obj, "", settings)
 	tc.getObject(tc.obj, "", true)
 
-	for _, ver := range tc.listVersions().DeleteMarker {
+	versions := tc.listVersions()
+	for _, ver := range versions.DeleteMarker {
 		if ver.IsLatest {
 			tc.deleteObject(tc.obj, ver.Object.Version(), settings)
 		}