diff --git a/doh-client/client.go b/doh-client/client.go
index 9c1e4a7..d768f10 100644
--- a/doh-client/client.go
+++ b/doh-client/client.go
@@ -155,7 +155,7 @@ func NewClient(conf *config.Config) (c *Client, err error) {
 	switch c.conf.Upstream.UpstreamSelector {
 	case config.NginxWRR:
 		if c.conf.Other.Verbose {
-			log.Println(config.NginxWRR, " mode start")
+			log.Println(config.NginxWRR, "mode start")
 		}
 
 		s := selector.NewNginxWRRSelector(time.Duration(c.conf.Other.Timeout) * time.Second)
@@ -175,7 +175,7 @@ func NewClient(conf *config.Config) (c *Client, err error) {
 
 	case config.LVSWRR:
 		if c.conf.Other.Verbose {
-			log.Println(config.LVSWRR, " mode start")
+			log.Println(config.LVSWRR, "mode start")
 		}
 
 		s := selector.NewLVSWRRSelector(time.Duration(c.conf.Other.Timeout) * time.Second)
@@ -195,7 +195,7 @@ func NewClient(conf *config.Config) (c *Client, err error) {
 
 	default:
 		if c.conf.Other.Verbose {
-			log.Println(config.Random, " mode start")
+			log.Println(config.Random, "mode start")
 		}
 
 		// if selector is invalid or random, use random selector, or should we stop program and let user knows he is wrong?
diff --git a/doh-client/selector/randomSelector.go b/doh-client/selector/randomSelector.go
index 9509845..cd2880c 100644
--- a/doh-client/selector/randomSelector.go
+++ b/doh-client/selector/randomSelector.go
@@ -42,7 +42,7 @@ func (rs *RandomSelector) Add(url string, upstreamType UpstreamType) (err error)
 }
 
 func (rs *RandomSelector) Get() *Upstream {
-	return rs.upstreams[rand.Intn(len(rs.upstreams)-1)]
+	return rs.upstreams[rand.Intn(len(rs.upstreams))]
 }
 
 func (rs *RandomSelector) StartEvaluate() {}