diff --git a/lego/sys/rpcx/selector.go b/lego/sys/rpcx/selector.go
index 13a045c06..759f86847 100644
--- a/lego/sys/rpcx/selector.go
+++ b/lego/sys/rpcx/selector.go
@@ -142,16 +142,8 @@ func (this *Selector) ParseRoutRules(rules string) (result []string) {
 			return
 		}
 	}
-
-	for k, _ := range this.servers {
-		iskeep := false
-		if k == rules {
-			iskeep = true
-			break
-		}
-		if !iskeep {
-			result = append(result, k)
-		}
+	if _, ok := this.servers[rules]; ok {
+		result = append(result, rules)
 	}
 	return
 }