diff --git a/app/dns/server.go b/app/dns/server.go
index 2c9f11a5..4d1eb16c 100644
--- a/app/dns/server.go
+++ b/app/dns/server.go
@@ -229,6 +229,7 @@ func New(ctx context.Context, config *Config) (*Server, error) {
 
 	if len(server.clients) == 0 {
 		server.clients = append(server.clients, NewLocalNameServer())
+		server.ipIndexMap = append(server.ipIndexMap, nil)
 	}
 
 	return server, nil