diff --git a/Alpha_shapes_3/doc_tex/Alpha_shapes_3/alpha3.tex b/Alpha_shapes_3/doc_tex/Alpha_shapes_3/alpha3.tex
index 401aa06ede9..1d08a3c6f62 100644
--- a/Alpha_shapes_3/doc_tex/Alpha_shapes_3/alpha3.tex
+++ b/Alpha_shapes_3/doc_tex/Alpha_shapes_3/alpha3.tex
@@ -307,7 +307,7 @@ and \ccc{CGAL::Fixed_alpha_shape_cell_base_3<Gt>}, respectively.
 
 
 
-\section{\ccc{Alpha_shape_3} or \ccc{Fixed_alpha_shape_3}}
+\section{\texorpdfstring{\ccc{Alpha_shape_3} or \ccc{Fixed_alpha_shape_3}}{Alpha\textunderscore{}shape\textunderscore{}3 or Fixed\textunderscore{}alpha\textunderscore{}shape\textunderscore{}3}}
 
 The class \ccc{CGAL::Alpha_shape_3<Dt>} represents the whole family
 of alpha shapes for a given set of points while the class \ccc{CGAL::Fixed_alpha_shape_3<Dt>}