diff --git a/README.md b/README.md
index 6531243..355ccbb 100644
--- a/README.md
+++ b/README.md
@@ -40,6 +40,7 @@ Usage of ut:
         specify source ip / interface
   -L string
         language, specify to en or zh (default "zh")
+  -b    use progress bar, disable example: -b=false (default true)
   -dns-servers string
         specify dns servers
   -f string