diff --git a/cfg/std.cfg b/cfg/std.cfg
index 12bf9e164..ce46ba034 100644
--- a/cfg/std.cfg
+++ b/cfg/std.cfg
@@ -4064,6 +4064,7 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
     </arg>
     <arg nr="2">
       <not-uninit/>
+      <valid>0:</valid>
     </arg>
   </function>
   <!-- Not part of standard, but widely supported by runtime libraries. -->