diff --git a/internal/multiplex/session.go b/internal/multiplex/session.go
index e1ab275..c808e2b 100644
--- a/internal/multiplex/session.go
+++ b/internal/multiplex/session.go
@@ -291,7 +291,7 @@ func (sesh *Session) passiveClose() error {
 func genRandomPadding() []byte {
 	lenB := make([]byte, 1)
 	common.CryptoRandRead(lenB)
-	pad := make([]byte, lenB[0]+1)
+	pad := make([]byte, int(lenB[0])+1)
 	common.CryptoRandRead(pad)
 	return pad
 }