diff --git a/doc/developer/advance.tex b/doc/developer/advance.tex
index be59ebef5d08937d35754ff73658dc514c802595..3aa40e5f9d34bb05d5296d13e370fb42bda538de 100644
--- a/doc/developer/advance.tex
+++ b/doc/developer/advance.tex
@@ -2938,9 +2938,9 @@ module Print =
 \end{ocamlcode}
 So it is a boolean parameter initialized by default to
 \texttt{false}. The declared interface for this module is simply
-\scodeidx{Parameter\_sig}{Int}
+\scodeidx{Parameter\_sig}{Bool}
 \begin{ocamlcode}
-module Print: Parameter_sig.Int
+module Print: Parameter_sig.Bool
 \end{ocamlcode}
 
 Another example is the parameter corresponding to the option