diff --git a/engine/packet.go b/engine/packet.go
index c784572..8d5354e 100644
--- a/engine/packet.go
+++ b/engine/packet.go
@@ -77,7 +77,7 @@ func ParseTCP(transport []byte) (TCPInfo, []byte, bool) {
 		FIN:     flags&0x01 != 0,
 		RST:     flags&0x04 != 0,
 		ACK:     flags&0x10 != 0,
-	}, transport[dataOff : dataOff+uint8(payloadLen)], true
+	}, transport[dataOff : int(dataOff)+payloadLen], true
 }
 
 func ParseUDP(transport []byte) (UDPInfo, []byte, bool) {