diff --git a/vlib/flag/README.md b/vlib/flag/README.md
index 444cbf60de..da1b8a4cd0 100644
--- a/vlib/flag/README.md
+++ b/vlib/flag/README.md
@@ -24,7 +24,7 @@ fn main() {
 	mut fp := flag.new_flag_parser(os.args)
 	fp.application('flag_example_tool')
 	fp.version('v0.0.1')
-	fp.limit_free_args(0, 0)? // comment this, if you expect arbitrary texts after the options
+	fp.limit_free_args(0, 0)! // comment this, if you expect arbitrary texts after the options
 	fp.description('This tool is only designed to show how the flag lib is working')
 	fp.skip_executable()
 	an_int := fp.int('an_int', 0, 0o123, 'some int to define 0o123 is its default value')