diff --git a/src/pe/cr/ContactResolvers.h b/src/pe/cr/ContactResolvers.h
index d90b6783559c68628ca8f0d91f8b5288a7129d56..f0b328974b6ca0b08b7b92624b275df93ef1e6fe 100644
--- a/src/pe/cr/ContactResolvers.h
+++ b/src/pe/cr/ContactResolvers.h
@@ -1,3 +1,25 @@
+//======================================================================================================================
+//
+//  This file is part of waLBerla. waLBerla is free software: you can
+//  redistribute it and/or modify it under the terms of the GNU General Public
+//  License as published by the Free Software Foundation, either version 3 of
+//  the License, or (at your option) any later version.
+//
+//  waLBerla 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 General Public License
+//  for more details.
+//
+//  You should have received a copy of the GNU General Public License along
+//  with waLBerla (see COPYING.txt). If not, see <http://www.gnu.org/licenses/>.
+//
+//! \file ContactResolvers.h
+//! \author Klaus Iglberger
+//! \author Sebastian Eibl <sebastian.eibl@fau.de>
+//! \brief Header file for DEM contact models
+//
+//======================================================================================================================
+
 #pragma once
 
 #include "pe/Types.h"
@@ -11,7 +33,7 @@ namespace cr {
 
 class ResolveContactSpringDashpotHaffWerner {
 public:
-   void operator()( ContactID c ) const
+   void operator()( ContactID c, const real_t /*dt*/ ) const
    {
       WALBERLA_LOG_DETAIL( "resolving contact: " << c->getID() );
       BodyID b1( c->getBody1()->getTopSuperBody() );
diff --git a/src/pe/cr/DEM.impl.h b/src/pe/cr/DEM.impl.h
index 3a910f72cacde157d4d50cbbba716b43e32f5aed..c64669ba210b48ca9f8101d7c09883c10405cc73 100644
--- a/src/pe/cr/DEM.impl.h
+++ b/src/pe/cr/DEM.impl.h
@@ -13,7 +13,7 @@
 //  You should have received a copy of the GNU General Public License along
 //  with waLBerla (see COPYING.txt). If not, see <http://www.gnu.org/licenses/>.
 //
-//! \file DEM.cpp
+//! \file DEM.impl.h
 //! \author Klaus Iglberger
 //! \author Sebastian Eibl <sebastian.eibl@fau.de>
 //! \brief Source file for the DEM solver
@@ -88,7 +88,7 @@ void DEMSolver<Integrator,ContactResolver>::timestep( real_t dt )
          if (shouldContactBeTreated( &(*cIt), currentBlock.getAABB() ))
          {
             ++numberOfContactsTreated_;
-            resolveContact_( &(*cIt) );
+            resolveContact_( &(*cIt), dt);
          }
       }
 
diff --git a/src/pe/cr/Integrators.h b/src/pe/cr/Integrators.h
index 7675caf6d51f7ce27b6f015e68bafdb14654ac9d..30b56e50a9e308917872d03156447d9e3b520157 100644
--- a/src/pe/cr/Integrators.h
+++ b/src/pe/cr/Integrators.h
@@ -1,3 +1,25 @@
+//======================================================================================================================
+//
+//  This file is part of waLBerla. waLBerla is free software: you can
+//  redistribute it and/or modify it under the terms of the GNU General Public
+//  License as published by the Free Software Foundation, either version 3 of
+//  the License, or (at your option) any later version.
+//
+//  waLBerla 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 General Public License
+//  for more details.
+//
+//  You should have received a copy of the GNU General Public License along
+//  with waLBerla (see COPYING.txt). If not, see <http://www.gnu.org/licenses/>.
+//
+//! \file Integrators.h
+//! \author Klaus Iglberger
+//! \author Sebastian Eibl <sebastian.eibl@fau.de>
+//! \brief Integrators for the DEM collision resolver
+//
+//======================================================================================================================
+
 #pragma once
 
 #include "pe/Types.h"