diff --git a/Solver_interface/doc/Solver_interface/CGAL/Eigen_solver_traits.h b/Solver_interface/doc/Solver_interface/CGAL/Eigen_solver_traits.h
index a22a9812b50..c758ed4ca92 100644
--- a/Solver_interface/doc/Solver_interface/CGAL/Eigen_solver_traits.h
+++ b/Solver_interface/doc/Solver_interface/CGAL/Eigen_solver_traits.h
@@ -7,7 +7,7 @@ namespace CGAL {
 The class `Eigen_solver_traits` provides an interface to the sparse solvers of \ref thirdpartyEigen "Eigen".
 The version 3.1 (or greater) of \ref thirdpartyEigen "Eigen" must be available on the system. 
 
-\cgalModels `SparseLinearAlgebraTraitsWithFactor_d` and `#NormalEquationSparseLinearAlgebraTraits_d`
+\cgalModels `SparseLinearAlgebraTraitsWithFactor_d` and `NormalEquationSparseLinearAlgebraTraits_d`
 
 
 `T`: a sparse solver of \ref thirdpartyEigen "Eigen". The default solver is the iterative bi-congugate gradient stabilized solver 
diff --git a/Surface_mesh_skeletonization/doc/Surface_mesh_skeletonization/Concepts/NormalEquationSparseLinearAlgebraTraitsWithFactor_d.h b/Solver_interface/doc/Solver_interface/Concepts/NormalEquationSparseLinearAlgebraTraitsWithFactor_d.h
similarity index 100%
rename from Surface_mesh_skeletonization/doc/Surface_mesh_skeletonization/Concepts/NormalEquationSparseLinearAlgebraTraitsWithFactor_d.h
rename to Solver_interface/doc/Solver_interface/Concepts/NormalEquationSparseLinearAlgebraTraitsWithFactor_d.h