diff --git a/relay/prover.go b/relay/prover.go
index 7f1de0a..51ef11c 100644
--- a/relay/prover.go
+++ b/relay/prover.go
@@ -261,17 +261,23 @@ func aggregateMessages(
 		messages = nil
 		signatures = nil
 		for i, b := range batches {
-			m := elc.MsgAggregateMessages{
-				Signer:     b.Signer,
-				Messages:   b.Messages,
-				Signatures: b.Signatures,
-			}
-			resp, err := messageAggregator(context.TODO(), &m)
-			if err != nil {
-				return nil, fmt.Errorf("failed to aggregate messages: i=%v msg=%v %w", i, m, err)
+			logger.Info("aggregateMessages", "batch_index", i, "num_messages", len(b.Messages))
+			if len(b.Messages) == 1 {
+				messages = append(messages, b.Messages[0])
+				signatures = append(signatures, b.Signatures[0])
+			} else {
+				m := elc.MsgAggregateMessages{
+					Signer:     b.Signer,
+					Messages:   b.Messages,
+					Signatures: b.Signatures,
+				}
+				resp, err := messageAggregator(context.TODO(), &m)
+				if err != nil {
+					return nil, fmt.Errorf("failed to aggregate messages: batch_index=%v msg=%v %w", i, m, err)
+				}
+				messages = append(messages, resp.Message)
+				signatures = append(signatures, resp.Signature)
 			}
-			messages = append(messages, resp.Message)
-			signatures = append(signatures, resp.Signature)
 		}
 	}
 }
diff --git a/relay/prover_test.go b/relay/prover_test.go
index 7d54099..eb4ffac 100644
--- a/relay/prover_test.go
+++ b/relay/prover_test.go
@@ -12,14 +12,14 @@ import (
 )
 
 func TestSplitIntoMultiBatch(t *testing.T) {
-	var M = func(n uint64) []byte {
-		return []byte(fmt.Sprintf("message-%d", n))
+	var M = func(n uint8) []byte {
+		return []byte(fmt.Sprintf("message-%03d", n))
 	}
-	var S = func(n uint64) []byte {
-		return []byte(fmt.Sprintf("signature-%d", n))
+	var S = func(n uint8) []byte {
+		return []byte(fmt.Sprintf("signature-%03d", n))
 	}
-	var Signer = func(n uint64) []byte {
-		return []byte(fmt.Sprintf("signer-%d", n))
+	var Signer = func(n uint8) []byte {
+		return []byte(fmt.Sprintf("signer-%03d", n))
 	}
 	var cases = []struct {
 		Messages         [][]byte
@@ -100,14 +100,14 @@ func TestSplitIntoMultiBatch(t *testing.T) {
 }
 
 func TestAggregateMessages(t *testing.T) {
-	var M = func(n uint64) []byte {
-		return []byte(fmt.Sprintf("message-%d", n))
+	var M = func(n uint8) []byte {
+		return []byte(fmt.Sprintf("message-%03d", n))
 	}
-	var S = func(n uint64) []byte {
-		return []byte(fmt.Sprintf("signature-%d", n))
+	var S = func(n uint8) []byte {
+		return []byte(fmt.Sprintf("signature-%03d", n))
 	}
-	var Signer = func(n uint64) []byte {
-		return []byte(fmt.Sprintf("signer-%d", n))
+	var Signer = func(n uint8) []byte {
+		return []byte(fmt.Sprintf("signer-%03d", n))
 	}
 
 	err := log.InitLogger("DEBUG", "text", "stdout")
@@ -158,22 +158,46 @@ func TestAggregateMessages(t *testing.T) {
 			BatchSize:  2,
 			Error:      false,
 		},
+		{
+			Messages:   [][]byte{M(0), M(1), M(2), M(3)},
+			Signatures: [][]byte{S(0), S(1), S(2), S(3)},
+			Signer:     Signer(0),
+			BatchSize:  2,
+			Error:      false,
+		},
+		{
+			Messages:   [][]byte{M(0), M(1), M(2), M(3), M(4)},
+			Signatures: [][]byte{S(0), S(1), S(2), S(3), S(4)},
+			Signer:     Signer(0),
+			BatchSize:  2,
+			Error:      false,
+		},
 	}
 
 	for i, c := range cases {
 		t.Run(fmt.Sprintf("case-%d", i), func(t *testing.T) {
 			require := require.New(t)
-			_, err := aggregateMessages(logger, c.BatchSize, mockMessageAggregator, c.Messages, c.Signatures, c.Signer)
+			res, err := aggregateMessages(logger, c.BatchSize, mockMessageAggregator, c.Messages, c.Signatures, c.Signer)
 			if c.Error {
 				require.Error(err)
 				return
 			} else {
 				require.NoError(err)
 			}
+			require.Equal(res.ProxyMessage, concatBytes(c.Messages))
+			require.Equal(res.Signatures[0], concatBytes(c.Signatures))
 		})
 	}
 }
 
+func concatBytes(bzs [][]byte) []byte {
+	var res []byte
+	for _, b := range bzs {
+		res = append(res, b...)
+	}
+	return res
+}
+
 func mockMessageAggregator(_ context.Context, in *elc.MsgAggregateMessages, _ ...grpc.CallOption) (*elc.MsgAggregateMessagesResponse, error) {
 	var res elc.MsgAggregateMessagesResponse
 	if len(in.Messages) != len(in.Signatures) {