diff --git a/execution/gethexec/executionengine.go b/execution/gethexec/executionengine.go
index 3ef894d402..e841a93529 100644
--- a/execution/gethexec/executionengine.go
+++ b/execution/gethexec/executionengine.go
@@ -234,6 +234,9 @@ func MessageFromTxes(header *arbostypes.L1IncomingMessageHeader, txes types.Tran
 			l2Message = append(l2Message, txBytes...)
 		}
 	}
+	if len(l2Message) > arbostypes.MaxL2MessageSize {
+		return nil, errors.New("l2message too long")
+	}
 	return &arbostypes.L1IncomingMessage{
 		Header: header,
 		L2msg:  l2Message,