diff --git a/zooid/instance.go b/zooid/instance.go
index d3949ff..78b0b9d 100644
--- a/zooid/instance.go
+++ b/zooid/instance.go
@@ -176,5 +176,5 @@ func (instance *Instance) RejectConnection(r *http.Request) bool {
 }
 
 func (instance *Instance) PreventBroadcast(ws *khatru.WebSocket, event nostr.Event) bool {
-	return event.Kind == 28934
+	return event.Kind == AUTH_JOIN
 }
diff --git a/zooid/util.go b/zooid/util.go
index 9cfe94c..10942df 100644
--- a/zooid/util.go
+++ b/zooid/util.go
@@ -6,6 +6,11 @@ import (
 	"sync"
 )
 
+const (
+	AUTH_JOIN   = 28934
+	AUTH_INVITE = 28935
+)
+
 var (
 	env     map[string]string
 	envOnce sync.Once