diff --git a/Number_types/doc/Number_types/PackageDescription.txt b/Number_types/doc/Number_types/PackageDescription.txt
index 430ee8ad3882..84bfd6debbdc 100644
--- a/Number_types/doc/Number_types/PackageDescription.txt
+++ b/Number_types/doc/Number_types/PackageDescription.txt
@@ -18,9 +18,6 @@
 /// \defgroup nt_cgal CGAL Number Types
 /// \ingroup PkgNumberTypesRef
 
-/// \defgroup nt_cgal CGAL Number Types
-/// \ingroup PkgNumberTypesRef
-
 /// \defgroup nt_rrational Relates Rational
 /// \ingroup PkgNumberTypesRef