diff --git a/constant/sniffer.go b/constant/sniffer.go
index c19b068c..0592b87a 100644
--- a/constant/sniffer.go
+++ b/constant/sniffer.go
@@ -8,6 +8,7 @@ type Sniffer interface {
 
 const (
 	TLS SnifferType = iota
+        HTTP SnifferType
 )
 
 var (