diff --git a/internal/tlv/t193.go b/internal/tlv/t193.go
index dd42cf87..b342245b 100644
--- a/internal/tlv/t193.go
+++ b/internal/tlv/t193.go
@@ -6,7 +6,7 @@ func T193(ticket string) []byte {
 	return binary.NewWriterF(func(w *binary.Writer) {
 		w.WriteUInt16(0x193)
 		pos := w.FillUInt16()
-		w.WriteString(ticket)
+		w.Write([]byte(ticket))
 		w.WriteUInt16At(pos, uint16(w.Len()-4))
 	})
 }