diff --git a/config.go b/config.go
index f26d2b1..1f68777 100644
--- a/config.go
+++ b/config.go
@@ -15,7 +15,7 @@ const (
 	MIN_PAYLOAD_SIZE    = MIN_MSS_SIZE - UDP_HEADER_SIZE - SRT_HEADER_SIZE
 	MAX_PAYLOAD_SIZE    = MAX_MSS_SIZE - UDP_HEADER_SIZE - SRT_HEADER_SIZE
 	MIN_PASSPHRASE_SIZE = 10
-	MAX_PASSPHRASE_SIZE = 79
+	MAX_PASSPHRASE_SIZE = 80
 	MAX_STREAMID_SIZE   = 512
 	SRT_VERSION         = 0x010401
 )