diff --git a/gcc/ada/doc/gnat_ugn/gnat_utility_programs.rst b/gcc/ada/doc/gnat_ugn/gnat_utility_programs.rst
index 883f0121263..56dd7beb7a0 100644
--- a/gcc/ada/doc/gnat_ugn/gnat_utility_programs.rst
+++ b/gcc/ada/doc/gnat_ugn/gnat_utility_programs.rst
@@ -2153,18 +2153,18 @@ building specialized scripts.
            A_Very_Very_Very_Very_Very_Very_Very_Very_Long_One);
 
 
-   .. index:: --call_threshold (gnatpp)
+   .. index:: --call-threshold (gnatpp)
 
-   :switch:`--call_threshold={nnn}`
+   :switch:`--call-threshold={nnn}`
      If the number of parameter associations is greater than ``nnn`` and if at
      least one association uses named notation, start each association from
      a new line. If ``nnn`` is 0, no check for the number of associations
      is made; this is the default.
 
 
-   .. index:: --par_threshold (gnatpp)
+   .. index:: --par-threshold (gnatpp)
 
-   :switch:`--par_threshold={nnn}`
+   :switch:`--par-threshold={nnn}`
      If the number of parameter specifications is greater than ``nnn``
      (or equal to ``nnn`` in case of a function), start each specification from
      a new line. If ``nnn`` is 0, and :switch:`--no-separate-is` was not specified, then