diff --git a/src/bem_grid_polonski.hh b/src/bem_grid_polonski.hh
index e56c938..158b2c5 100644
--- a/src/bem_grid_polonski.hh
+++ b/src/bem_grid_polonski.hh
@@ -1,79 +1,78 @@
 /**
  *
  * @author Lucas Frérot <lucas.frerot@epfl.ch>
  *
  * @section LICENSE
  *
  * Copyright (©)  2016 EPFL  (Ecole Polytechnique  Fédérale de
  * Lausanne)  Laboratory (LSMS  -  Laboratoire de  Simulation  en Mécanique  des
  * Solides)
  *
  * Tamaas is free  software: you can redistribute it and/or  modify it under the
  * terms  of the  GNU Lesser  General Public  License as  published by  the Free
  * Software Foundation, either version 3 of the License, or (at your option) any
  * later version.
  *
  * Tamaas is  distributed in the  hope that it  will be useful, but  WITHOUT ANY
  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  * A  PARTICULAR PURPOSE. See  the GNU  Lesser General  Public License  for more
  * details.
  *
  * You should  have received  a copy  of the GNU  Lesser General  Public License
  * along with Tamaas. If not, see <http://www.gnu.org/licenses/>.
  *
  */
 
 /* -------------------------------------------------------------------------- */
 #ifndef __BEM_GRID_POLONSKI_HH__
 #define __BEM_GRID_POLONSKI_HH__
 /* -------------------------------------------------------------------------- */
 #include "surface.hh"
 #include "grid.hh"
 #include "types.hh"
 #include "bem_grid_kato.hh"
-#include "friction_helper.hh"
 /* -------------------------------------------------------------------------- */
 
 __BEGIN_TAMAAS__
 
 // typedef for swig
 typedef Grid<Real, 1> Grid1dReal;
 
 /**
  * @brief multi component implementation of Polonski algorithm
  * This method's main unknown is the pressure.
  */
 class BemGridPolonski : public BemGridKato {
 public:
   /// Constructor
   BemGridPolonski(Surface<Real> & surface);
   /// Destructor
   virtual ~BemGridPolonski();
 
 public:
 /* -------------------------------------------------------------------------- */
 /* Actual computations                                                        */
 /* -------------------------------------------------------------------------- */
   /// Compute equilibrium
   virtual void computeEquilibrium(Real tol, const Grid<Real, 1> & p_target);
   /// Compute gap functional
   Real computeGradientNorm();
   /// Compute optimal step size
   Real computeOptimalStep();
   /// Center field on contact area
   void centerOnContactArea(Grid<Real, 2> & field);
   /// Update search direction
   void updateSearchDirection(Real delta, Real G, Real G_old);
   /// Update tractions
   Real updateTractions(Real tau);
   /// Set pressure on all points
   void setPressure(const Grid<Real, 1> & p_target);
 
 protected:
   Grid<Real, 2> search_direction;
   Grid<Real, 2> projected_search_direction;
 };
 
 __END_TAMAAS__
 
 #endif // __BEM_GRID_POLONSKI_HH__