diff --git a/lib/xchain/merkle.go b/lib/xchain/merkle.go
index c1cba5c8..1ba5f077 100644
--- a/lib/xchain/merkle.go
+++ b/lib/xchain/merkle.go
@@ -102,6 +102,15 @@ func msgLeaf(msg Msg) ([32]byte, error) {
 	return merkle.StdLeafHash(DSTMessage, bz), nil
 }
 
+func MsgLeaf(msg Msg) ([32]byte, error) {
+	bz, err := encodeMsg(msg)
+	if err != nil {
+		return [32]byte{}, errors.Wrap(err, "encode message")
+	}
+
+	return merkle.StdLeafHash(DSTMessage, bz), nil
+}
+
 func submissionHeaderLeaf(attHeader AttestHeader, blockHeader BlockHeader) ([32]byte, error) {
 	bz, err := encodeSubmissionHeader(attHeader, blockHeader)
 	if err != nil {
diff --git a/relayer/app/creator_test.go b/relayer/app/creator_test.go
index c7978a3b..2b99b911 100644
--- a/relayer/app/creator_test.go
+++ b/relayer/app/creator_test.go
@@ -4,6 +4,7 @@ import (
 	"math/rand"
 	"testing"
 	"time"
+	"encoding/hex"
 
 	"github.com/omni-network/omni/halo/attest/voter"
 	"github.com/omni-network/omni/lib/cchain"
@@ -20,6 +21,100 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestMsgTreeOrdering(t *testing.T) {
+	t.Parallel()
+
+	var (
+		SourceChainID = uint64(1)
+		DestChainID   = uint64(2)
+	)
+
+	privKey := k1.GenPrivKey()
+	addr, err := k1util.PubKeyToAddress(privKey.PubKey())
+	require.NoError(t, err)
+
+	fuzzer := fuzz.New().NilChance(0).Funcs(
+		func(e *xchain.Msg, c fuzz.Continue) {
+			e.DestChainID = DestChainID
+			e.SourceChainID = SourceChainID
+			e.DestAddress = common.Address(crypto.CRandBytes(20))
+			e.SourceMsgSender = common.Address(crypto.CRandBytes(20))
+			e.Data = crypto.CRandBytes(100)
+		},
+	)
+
+	var block xchain.Block
+	fuzzer.NilChance(0).NumElements(4, 4).Fuzz(&block)
+	require.NotEmpty(t, block.Msgs)
+	// Ensure msg.LogIndex is increasing
+	for i := 1; i < len(block.Msgs); i++ {
+		block.Msgs[i].LogIndex = block.Msgs[i-1].LogIndex + 1 + uint64(rand.Intn(1000))
+	}
+
+	var attestHeader xchain.AttestHeader
+	fuzzer.Fuzz(&attestHeader)
+	attestHeader.ChainVersion.ID = block.ChainID // Align headers
+
+	var valSetID uint64
+	fuzzer.Fuzz(&valSetID)
+
+	// make all msg offset sequential
+	for i := range block.Msgs {
+		block.Msgs[i].StreamOffset = uint64(i)
+	}
+
+	vote, err := voter.CreateVote(privKey, attestHeader, block)
+	require.NoError(t, err)
+	header, err := vote.BlockHeader.ToXChain()
+	require.NoError(t, err)
+	require.Equal(t, block.BlockHeader, header)
+	require.Equal(t, addr, common.Address(vote.Signature.ValidatorAddress))
+
+	tree, err := xchain.NewMsgTree(block.Msgs)
+	require.NoError(t, err)
+	treeRoot := tree.MsgRoot()
+	t.Log("***** MsgTree root:", hex.EncodeToString(treeRoot[:]))
+
+	// create new Msgs
+	cMsgs := make([]xchain.Msg, len(block.Msgs))
+	copy(cMsgs, block.Msgs)
+
+	s := len(cMsgs)-1
+	a, b := cMsgs[s], cMsgs[s-1]
+
+	// swap last two messages
+	cMsgs[s], cMsgs[s-1] = b, a
+	// swap LogIndices
+	cMsgs[s].LogIndex = a.LogIndex
+	cMsgs[s-1].LogIndex = b.LogIndex
+	lastLeafOrig, err := xchain.MsgLeaf(block.Msgs[s])
+	require.NoError(t, err)
+	lastLeafNew, err := xchain.MsgLeaf(cMsgs[s])
+	require.NoError(t, err)
+	require.NotEqual(t, lastLeafOrig, lastLeafNew)
+
+	// recalculate the tree
+	newTree, err := xchain.NewMsgTree(cMsgs)
+	require.NoError(t, err)
+	newTreeRoot := newTree.MsgRoot()
+	t.Log("***** MsgTree root:", hex.EncodeToString(newTreeRoot[:]))
+
+	blockHeader, err := vote.BlockHeader.ToXChain()
+	require.NoError(t, err)
+
+	sig, err := vote.Signature.ToXChain()
+	require.NoError(t, err)
+
+	att := xchain.Attestation{
+		AttestHeader:   vote.AttestHeader.ToXChain(),
+		BlockHeader:    blockHeader,
+		ValidatorSetID: valSetID,
+		MsgRoot:        [32]byte(vote.MsgRoot),
+		Signatures:     []xchain.SigTuple{sig},
+	}
+	t.Log("***** Attestation MsgTree root:", hex.EncodeToString(att.MsgRoot[:]))
+}
+
 func TestCreatorService_CreateSubmissions(t *testing.T) {
 	t.Parallel()