diff --git a/src/OpenMesh/Apps/Decimating/DecimaterViewerWidget.hh b/src/OpenMesh/Apps/Decimating/DecimaterViewerWidget.hh
index caad4bab201986d26b5e1a9705d2cbe9afe1687c..26a21d818ce581069716621da798c17c5a09b399 100644
--- a/src/OpenMesh/Apps/Decimating/DecimaterViewerWidget.hh
+++ b/src/OpenMesh/Apps/Decimating/DecimaterViewerWidget.hh
@@ -103,13 +103,11 @@ public:
   typedef MeshViewerWidget inherited_t;
 
   typedef Decimater::DecimaterT<mesh_t>                decimater_t;  
-  typedef Decimater::ModQuadricT< mesh_t >        mod_quadric_t;
-  typedef Decimater::ModNormalFlippingT< mesh_t > mod_nf_t;
+  typedef Decimater::ModQuadricT< mesh_t >::Handle        mod_quadric_t;
+  typedef Decimater::ModNormalFlippingT< mesh_t >::Handle mod_nf_t;
 
   // object types
   typedef std::auto_ptr< decimater_t   >   decimater_o;
-  typedef std::auto_ptr< mod_quadric_t >   mod_quadric_o;
-  typedef std::auto_ptr< mod_nf_t      >   mod_nf_o;
 
   /// default constructor
   DecimaterViewerWidget(QWidget* _parent=0)
@@ -148,14 +146,11 @@ public: // inherited
         decimater_o  tmp( new decimater_t  ( mesh() ) );
         decimater_ = tmp;
       }
-      {
-        mod_quadric_o  tmp( new mod_quadric_t( mesh() ) );
-        mod_quadric_ = tmp;
-      }
-      {
-        mod_nf_o       tmp( new mod_nf_t     ( mesh() ) );
-        mod_nf_      = tmp;
-      }
+
+      decimater_->add(mod_quadric_);
+      decimater_->module(mod_quadric_).set_binary(false);
+
+      decimater_->add(mod_nf_);
 
       decimater_->initialize();
     }
@@ -177,8 +172,8 @@ private:
   QTimer           *timer_;
 
   decimater_o       decimater_;  
-  mod_quadric_o     mod_quadric_;
-  mod_nf_o          mod_nf_;
+  mod_quadric_t     mod_quadric_;
+  mod_nf_t          mod_nf_;
 
   size_t            steps_;
 };
diff --git a/src/OpenMesh/Apps/Decimating/decimater.cc b/src/OpenMesh/Apps/Decimating/decimater.cc
index 8d61ba8b5d034af5eb4329f60af5bb2dda25c4d8..7f2c20e51b382a0a717d9af10d30fbfb140493bc 100644
--- a/src/OpenMesh/Apps/Decimating/decimater.cc
+++ b/src/OpenMesh/Apps/Decimating/decimater.cc
@@ -271,6 +271,7 @@ decimate(const std::string &_ifname,
        decimater.add(modEL);
        if (_opt.EL.has_value())
          decimater.module( modEL ).set_edge_length( _opt.EL ) ;
+       decimater.module(modEL).set_binary(false);
      }
 
      typename OpenMesh::Decimater::ModHausdorffT <Mesh>::Handle modHD;
@@ -319,6 +320,7 @@ decimate(const std::string &_ifname,
        decimater.add(modQ);
        if (_opt.Q.has_value())
          decimater.module( modQ ).set_max_err( _opt.Q );
+       decimater.module(modQ).set_binary(false);
      }
 
      typename OpenMesh::Decimater::ModRoundnessT<Mesh>::Handle      modR;
@@ -345,6 +347,7 @@ decimate(const std::string &_ifname,
        if (!rc)
        {
          std::cerr << "  initializing failed!" << std::endl;
+         std::cerr << "  maybe no priority module or more than one were defined!" << std::endl;
          return false;
        }
      }
@@ -538,15 +541,16 @@ void usage_and_exit(int xcode)
   std::cerr << std::endl;
   std::cerr << "Modules:\n\n";
   std::cerr << "  AR[:ratio]      - ModAspectRatio\n";
-  std::cerr << "  EL[:legth]      - ModEdgeLength\n";
+  std::cerr << "  EL[:legth]      - ModEdgeLength*\n";
   std::cerr << "  HD[:distance]   - ModHausdorff\n";
   std::cerr << "  IS              - ModIndependentSets\n";
   std::cerr << "  ND[:angle]      - ModNormalDeviation\n";
   std::cerr << "  NF[:angle]      - ModNormalFlipping\n";
   std::cerr << "  PM[:file name]  - ModProgMesh\n";
-  std::cerr << "  Q[:error]       - ModQuadric\n";
+  std::cerr << "  Q[:error]       - ModQuadric*\n";
   std::cerr << "  R[:angle]       - ModRoundness\n";
   std::cerr << "    0 < angle < 60\n";
+  std::cerr << "  *: priority module. Decimater needs one of them (not more).\n";
 
   exit( xcode );
 }