diff --git a/src/plugins/wp/doc/manual/wp_plugin.tex b/src/plugins/wp/doc/manual/wp_plugin.tex
index 361b7e2e94873ee4281b51394175d7d8dd1e58a7..39f4248a2722b6a17b81de391a20b989d798b83a 100644
--- a/src/plugins/wp/doc/manual/wp_plugin.tex
+++ b/src/plugins/wp/doc/manual/wp_plugin.tex
@@ -839,7 +839,8 @@ interface of the programmatic API.
   functions \texttt{f$_1$},...,\texttt{f$_n$} (defaults to none).
 \item [\tt -wp-bhv <b$_1$,...,b$_n$>] selects annotations for behaviors
   \texttt{b$_1$},...\texttt{b$_n$} (defaults to all behaviors) of the
-  selected functions.
+  selected functions (the name \texttt{default!} can be used to select
+  the default anonymous behavior).
 \item [\tt -wp-prop <p$_1$,...,p$_n$>] selects properties having
   \texttt{p$_1$} or ...\texttt{p$_n$} as tagname (defaults to all
   properties). You may also replace a tagname by a
diff --git a/src/plugins/wp/wp_parameters.ml b/src/plugins/wp/wp_parameters.ml
index 05af49b24c04b158078bdbf666c85c4e0502578d..dcb847343ab591e43b845e2f32b103a9f776e0fe 100644
--- a/src/plugins/wp/wp_parameters.ml
+++ b/src/plugins/wp/wp_parameters.ml
@@ -97,7 +97,7 @@ module Behaviors =
     (struct
       let option_name = "-wp-bhv"
       let arg_name = "b,..."
-      let help = "Select only properties belonging to listed behaviors."
+      let help = "Select only properties belonging to listed behaviors (the name \"default!\" can be used to select the default anonymous behavior) of the selected functions (defaults to all behaviors)."
     end)
 let () = on_reset Behaviors.clear