diff --git a/management.go b/management.go
index 451b4c1..51a661b 100644
--- a/management.go
+++ b/management.go
@@ -187,7 +187,7 @@ func (m *MonfloManagement) genId(client *ClientInfo) {
 		if !m.checkIdExist(strconv.FormatInt(id, 10)) {
 			break
 		}
-		id = 10000000009 + 8*rand.Int63n(10000)
+		id = 10000000009 + 8*rand.Int63n(5)
 	}
 	client.StreamId = strconv.FormatInt(id, 10)
 }