diff --git a/relay/config.go b/relay/config.go
index 47e49e0..777e762 100644
--- a/relay/config.go
+++ b/relay/config.go
@@ -10,6 +10,8 @@ import (
 	"github.com/hyperledger-labs/yui-relayer/core"
 )
 
+const DefaultMessageAggregationBatchSize = 8
+
 var _ core.ProverConfig = (*ProverConfig)(nil)
 
 var _ codectypes.UnpackInterfacesMessage = (*ProverConfig)(nil)
@@ -43,6 +45,14 @@ func (pc ProverConfig) GetMrenclave() []byte {
 	return mrenclave
 }
 
+func (pc ProverConfig) GetMessageAggregationBatchSize() uint64 {
+	if pc.MessageAggregationBatchSize == 0 {
+		return DefaultMessageAggregationBatchSize
+	} else {
+		return pc.MessageAggregationBatchSize
+	}
+}
+
 func (pc ProverConfig) Validate() error {
 	// origin prover config validation
 	if err := pc.OriginProver.GetCachedValue().(core.ProverConfig).Validate(); err != nil {
@@ -60,8 +70,8 @@ func (pc ProverConfig) Validate() error {
 	if pc.KeyExpiration == 0 {
 		return fmt.Errorf("KeyExpiration must be greater than 0")
 	}
-	if pc.MessageAggregation && pc.MessageAggregationBatchSize < 2 {
-		return fmt.Errorf("MessageAggregationBatchSize must be greater than 1 if MessageAggregation is true")
+	if pc.MessageAggregation && pc.MessageAggregationBatchSize == 1 {
+		return fmt.Errorf("MessageAggregationBatchSize must be greater than 1 if MessageAggregation is true and MessageAggregationBatchSize is set")
 	}
 	return nil
 }
diff --git a/relay/prover.go b/relay/prover.go
index 4630851..fa897e0 100644
--- a/relay/prover.go
+++ b/relay/prover.go
@@ -217,7 +217,7 @@ func (pr *Prover) aggregateMessages(messages [][]byte, signatures [][]byte, sign
 		return nil, fmt.Errorf("aggregateMessages: messages and signatures must have the same length: messages=%v signatures=%v", len(messages), len(signatures))
 	}
 	for {
-		batches, err := splitIntoMultiBatch(messages, signatures, signer, pr.config.MessageAggregationBatchSize)
+		batches, err := splitIntoMultiBatch(messages, signatures, signer, pr.config.GetMessageAggregationBatchSize())
 		if err != nil {
 			return nil, err
 		}
@@ -271,6 +271,9 @@ func splitIntoMultiBatch(messages [][]byte, signatures [][]byte, signer []byte,
 	var res []*elc.MsgAggregateMessages
 	var currentMessages [][]byte
 	var currentBatchStartIndex uint64 = 0
+	if messageBatchSize < 2 {
+		return nil, fmt.Errorf("messageBatchSize must be greater than 1")
+	}
 	for i := 0; i < len(messages); i++ {
 		currentMessages = append(currentMessages, messages[i])
 		if uint64(len(currentMessages)) == messageBatchSize {