diff --git a/metadapta.go b/metadapta.go
index ca6a629..e9b8e56 100644
--- a/metadapta.go
+++ b/metadapta.go
@@ -10,6 +10,7 @@ import "git.tebibyte.media/sashakoshka/go-util/sync"
 const closeMethod = 0xFFFF
 const int64Max = int64((^uint64(0)) >> 1)
 
+
 // Party represents a side of a connection.
 type Party bool; const (
 	ServerSide Party = false
@@ -33,6 +34,7 @@ type a struct {
 // oriented transport such as TCP or UNIX domain stream sockets.
 func AdaptA(underlying net.Conn, party Party) Conn {
 	conn := &a {
+		sizeLimit:  defaultSizeLimit,
 		underlying: underlying,
 		party:      party,
 		transMap:   make(map[int64] *transA),
@@ -115,7 +117,7 @@ func (this *a) receive() {
 		clear(this.transMap)
 	}()
 	for {
-		transID, method, chunked, payload, err := decodeMessageA(this.underlying)
+		transID, method, chunked, payload, err := decodeMessageA(this.underlying, this.sizeLimit)
 		if err != nil {
 			this.err = fmt.Errorf("could not receive message: %w", err)
 			return
@@ -277,7 +279,16 @@ func encodeMessageA(writer io.Writer, trans int64, method uint16, data []byte) e
 	return err
 }
 
-func decodeMessageA(reader io.Reader) (transID int64, method uint16, chunked bool, payloadBuffer []byte, err error) {
+func decodeMessageA(
+	reader    io.Reader,
+	sizeLimit int64,
+) (
+	transID       int64,
+	method        uint16,
+	chunked       bool,
+	payloadBuffer []byte,
+	err           error,
+) {
 	headerBuffer := [18]byte { }
 	_, err = io.ReadFull(reader, headerBuffer[:])
 	if err != nil { return 0, 0, false, nil, err }
@@ -288,6 +299,9 @@ func decodeMessageA(reader io.Reader) (transID int64, method uint16, chunked boo
 	size, err := tape.DecodeI64[uint64](headerBuffer[10:18])
 	if err != nil { return 0, 0, false, nil, err }
 	chunked, size = splitCCBSize(size)
+	if size > uint64(sizeLimit) {
+		return 0, 0, false, nil, ErrPayloadTooLarge
+	}
 	payloadBuffer = make([]byte, int(size))
 	_, err = io.ReadFull(reader, payloadBuffer)
 	if err != nil { return 0, 0, false, nil, err }