diff --git a/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Concepts/AosTraits--ApproximatePoint_2.h b/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Concepts/AosTraits--ApproximatePoint_2.h
index aec9d5970d1..6d311aff303 100644
--- a/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Concepts/AosTraits--ApproximatePoint_2.h
+++ b/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Concepts/AosTraits--ApproximatePoint_2.h
@@ -20,7 +20,7 @@ public:
    * `p`'s \f$y\f$-coordinate (if `i == 1`).
    * \pre `i` is either 0 or 1.
    */
-  CGAL::Approximate_number_type operator()(AosTraits::Point_2 p, int i);
+  Approximate_number_type operator()(AosTraits::Point_2 p, int i);
 
   /// @}
 }; /* end AosTraits::Approximate_2 */
diff --git a/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Concepts/AosTraits--Approximate_2.h b/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Concepts/AosTraits--Approximate_2.h
index eb6f206082b..f1a3caaf62b 100644
--- a/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Concepts/AosTraits--Approximate_2.h
+++ b/Arrangement_on_surface_2/doc/Arrangement_on_surface_2/Concepts/AosTraits--Approximate_2.h
@@ -18,7 +18,7 @@ public:
 
   /*! obtains an approximation of `p`.
    */
-  CGAL::Approximate_point_2 operator()(AosTraits::Point_2 p);
+  Approximate_point_2 operator()(AosTraits::Point_2 p);
 
   /*! approximates a given \f$x\f$-monotone curve. It computes a sequence of
    * approximate points that represent an approximate polyline, and inserts