diff --git a/Combinatorial_map/include/CGAL/internal/Combinatorial_map_copy_functors.h b/Combinatorial_map/include/CGAL/internal/Combinatorial_map_copy_functors.h
index 7fbee1c0ec2..272d9151b99 100644
--- a/Combinatorial_map/include/CGAL/internal/Combinatorial_map_copy_functors.h
+++ b/Combinatorial_map/include/CGAL/internal/Combinatorial_map_copy_functors.h
@@ -25,7 +25,7 @@
 #include <CGAL/Dimension.h>
 #include <CGAL/Kernel_traits.h>
 #include <CGAL/Cartesian_converter.h>
-
+#include <CGAL/use.h>
 /* Definition of functors used internally to copy combinatorial maps attributes
  * (we need functors as attributes are stored in tuple, thus all the access
  *  must be done at compiling time).
@@ -346,6 +346,7 @@ struct Default_converter_cmap_attributes
   (const Map1& map1, Map2& map2, typename Map1::Dart_const_handle dh1,
    typename Map2::Dart_handle dh2) const
   {
+    CGAL_USE(dh2);
     CGAL_assertion( map1.template attribute<i>(dh1)!=Map1::null_handle );
     CGAL_assertion( map2.template attribute<i>(dh2)==Map2::null_handle );
     return internal::Create_attribute_if_same_info_cmap
@@ -363,6 +364,7 @@ struct Cast_converter_cmap_attributes
   (const Map1& map1, Map2& map2, typename Map1::Dart_const_handle dh1,
    typename Map2::Dart_handle dh2) const
   {
+    CGAL_USE(dh2);
     CGAL_assertion( map1.template attribute<i>(dh1)!=Map1::null_handle );
     CGAL_assertion( map2.template attribute<i>(dh2)==Map2::null_handle );
     typename Map2::template Attribute_handle<i>::type
diff --git a/Convex_decomposition_3/include/CGAL/Convex_decomposition_3/SM_walls.h b/Convex_decomposition_3/include/CGAL/Convex_decomposition_3/SM_walls.h
index 9f67275f95d..72337e4f75b 100644
--- a/Convex_decomposition_3/include/CGAL/Convex_decomposition_3/SM_walls.h
+++ b/Convex_decomposition_3/include/CGAL/Convex_decomposition_3/SM_walls.h
@@ -23,6 +23,7 @@
 #undef CGAL_NEF_DEBUG
 #define CGAL_NEF_DEBUG 227
 #include <CGAL/Nef_2/debug.h>
+#include <CGAL/use.h>
 
 namespace CGAL {
 
@@ -75,7 +76,7 @@ class SM_walls : SM_decorator<SMap> {
   }
 
   SHalfedge_handle find_cap(SVertex_handle sv, Sphere_point sp, Sphere_circle c) {
-
+    CGAL_USE(sp);
     CGAL_NEF_TRACEN( "find_cap " << sv->source()->point() << ":" << sv->point() 
 	      << " , sp : " << sp );
     /*
diff --git a/Kernel_d/include/CGAL/Kernel_d/Matrix__.h b/Kernel_d/include/CGAL/Kernel_d/Matrix__.h
index 978ecf814b2..d6f3fb9db05 100644
--- a/Kernel_d/include/CGAL/Kernel_d/Matrix__.h
+++ b/Kernel_d/include/CGAL/Kernel_d/Matrix__.h
@@ -26,6 +26,7 @@
 #define CGAL_MATRIX___H
 
 #include <CGAL/Kernel_d/Vector__.h>
+#include <CGAL/use.h>
 #include <new>
 #include <cstddef>                 // for std::size_t, std::ptrdiff_t
 
@@ -189,6 +190,7 @@ inline void deallocate_mat_space(vector_pointer*& vi, int d)
 
 inline void check_dimensions(const Matrix_<NT_,AL_>& mat) const
 { 
+  CGAL_USE(mat);
   CGAL_assertion_msg((dm_ == mat.dm_ && dn_ == mat.dn_), 
     "Matrix::check_dimensions: incompatible matrix dimensions.") ;
 }
diff --git a/Kernel_d/include/CGAL/Kernel_d/Vector__.h b/Kernel_d/include/CGAL/Kernel_d/Vector__.h
index b731d0ea23a..b4ba1085334 100644
--- a/Kernel_d/include/CGAL/Kernel_d/Vector__.h
+++ b/Kernel_d/include/CGAL/Kernel_d/Vector__.h
@@ -28,6 +28,7 @@
 #include <CGAL/basic.h>
 #include <CGAL/memory.h>
 #include <CGAL/Kernel_d/debug.h>
+#include <CGAL/use.h>
 
 #include <cmath>
 #include <memory>
@@ -120,6 +121,7 @@ protected:
 inline void 
 check_dimensions(const Vector_<NT_,AL_>& vec) const
 { 
+  CGAL_USE(vec);
   CGAL_assertion_msg((d_ == vec.d_), 
     "Vector_::check_dimensions: object dimensions disagree.");
 }
diff --git a/Minkowski_sum_3/include/CGAL/Minkowski_sum_3/Gaussian_map.h b/Minkowski_sum_3/include/CGAL/Minkowski_sum_3/Gaussian_map.h
index a3da591d1fd..33d6adec675 100644
--- a/Minkowski_sum_3/include/CGAL/Minkowski_sum_3/Gaussian_map.h
+++ b/Minkowski_sum_3/include/CGAL/Minkowski_sum_3/Gaussian_map.h
@@ -32,6 +32,8 @@
 #define CGAL_NEF_DEBUG 223
 #include <CGAL/Nef_2/debug.h>
 
+#include <CGAL/use.h>
+
 namespace CGAL {
 
 
@@ -169,7 +171,7 @@ class Gaussian_map :
     }
 
   public:
-      void visit(Vertex_const_handle v) {	CGAL_NEF_TRACEN( "Vertices " << v->point() );}
+      void visit(Vertex_const_handle v) { CGAL_USE(v); CGAL_NEF_TRACEN( "Vertices " << v->point() );}
       void visit(Halfedge_const_handle ) {}
       void visit(SHalfedge_const_handle ) {}
       void visit(SHalfloop_const_handle ) {}
diff --git a/Nef_3/include/CGAL/Nef_3/SNC_FM_decorator.h b/Nef_3/include/CGAL/Nef_3/SNC_FM_decorator.h
index c797b241d7e..211d7253e6a 100644
--- a/Nef_3/include/CGAL/Nef_3/SNC_FM_decorator.h
+++ b/Nef_3/include/CGAL/Nef_3/SNC_FM_decorator.h
@@ -32,6 +32,7 @@
 #undef CGAL_NEF_DEBUG
 #define CGAL_NEF_DEBUG 31
 #include <CGAL/Nef_2/debug.h>
+#include <CGAL/use.h>
 
 namespace CGAL {
 
@@ -135,8 +136,11 @@ Vertex_handle new_vertex(const Point& p) const
   return p.vertex(); }
 
 Halfedge_handle new_halfedge_pair_at_source(Vertex_handle v) 
-{ CGAL_NEF_TRACEN("new_edge "<<&*v<<" "<<edge_number+1);
-  return ++edge_number; }
+{ 
+  CGAL_USE(v);
+  CGAL_NEF_TRACEN("new_edge "<<&*v<<" "<<edge_number+1);
+  return ++edge_number; 
+}
 
 void supporting_segment(Halfedge_handle e, I it)
 { if ( From[it] != E() ) Support[e] = From[it]; }
@@ -215,7 +219,9 @@ int compare_xy(const Point_2& p1, const Point_2& p2) const {
 }
 
 Point_2 intersection(const Segment_2& s1, const Segment_2& s2) const
-{ CGAL_assertion(target(s1).vertex()==target(s2).vertex()); 
+{
+  CGAL_USE(s2);
+  CGAL_assertion(target(s1).vertex()==target(s2).vertex()); 
   return target(s1); }
 
 bool left_turn(const Point_3& p1, const Point_3& p2, const Point_3& p3) const
diff --git a/Nef_3/include/CGAL/Nef_3/SNC_external_structure.h b/Nef_3/include/CGAL/Nef_3/SNC_external_structure.h
index c34ac3cef94..676371a62e6 100644
--- a/Nef_3/include/CGAL/Nef_3/SNC_external_structure.h
+++ b/Nef_3/include/CGAL/Nef_3/SNC_external_structure.h
@@ -40,6 +40,8 @@
 #define CGAL_NEF_DEBUG 43
 #include <CGAL/Nef_2/debug.h>
 
+#include <CGAL/use.h>
+
 namespace CGAL {
 
 struct int_lt {
@@ -245,10 +247,12 @@ public:
     }
 
     void visit(Vertex_handle h) { 
+      CGAL_USE(h);
       CGAL_NEF_TRACEN("visit v  "<<h->point());
     }
 
     void visit(Halfedge_handle h) { 
+      CGAL_USE(h);
       CGAL_NEF_TRACEN("visit he "<< h->source()->point());
     }
 
diff --git a/Nef_S2/include/CGAL/Nef_S2/SM_overlayer.h b/Nef_S2/include/CGAL/Nef_S2/SM_overlayer.h
index 8450a4eaa24..d677995d531 100644
--- a/Nef_S2/include/CGAL/Nef_S2/SM_overlayer.h
+++ b/Nef_S2/include/CGAL/Nef_S2/SM_overlayer.h
@@ -46,6 +46,8 @@
 #include <LEDA/system/memory.h>
 #endif
 
+#include <CGAL/use.h>
+
 namespace CGAL {
 
 template <typename Decorator_, typename I>
@@ -114,7 +116,11 @@ struct SMO_from_segs {
   }
 
   void assert_equal_marks(Vertex_handle v1, Vertex_handle v2) const 
-  { CGAL_assertion(v1->mark()==v2->mark()); }
+  { 
+    CGAL_USE(v1);
+    CGAL_USE(v2);
+    CGAL_assertion(v1->mark()==v2->mark());
+  }
 
   void discard_info(Vertex_handle v) const 
   { 
@@ -126,7 +132,11 @@ struct SMO_from_segs {
   }
 
   void assert_equal_marks(Halfedge_handle e1, Halfedge_handle e2) const
-  { CGAL_assertion(e1->mark()==e2->mark()); }
+  {
+    CGAL_USE(e1);
+    CGAL_USE(e2);
+    CGAL_assertion(e1->mark()==e2->mark());
+  }
 
   void discard_info(Halfedge_handle ) const {}
 
@@ -281,7 +291,10 @@ Halfedge_handle halfedge_below(Vertex_handle v) const
 { return G.halfedge_below(v); }
 
 void assert_equal_marks(Vertex_handle v1, Vertex_handle v2) const 
-{ CGAL_NEF_TRACEV(G.mark(v1,0));CGAL_NEF_TRACEV(G.mark(v1,1));
+{
+  CGAL_USE(v1);
+  CGAL_USE(v2);
+  CGAL_NEF_TRACEV(G.mark(v1,0));CGAL_NEF_TRACEV(G.mark(v1,1));
   CGAL_NEF_TRACEV(G.mark(v2,0));CGAL_NEF_TRACEV(G.mark(v2,1));
   CGAL_assertion(G.mark(v1,0)==G.mark(v2,0)&&
 		 G.mark(v1,1)==G.mark(v2,1)); }
@@ -289,8 +302,12 @@ void discard_info(Vertex_handle v) const
 { G.discard_info(v); }
 
 void assert_equal_marks(Halfedge_handle e1, Halfedge_handle e2) const
-{ CGAL_assertion(G.mark(e1,0)==G.mark(e2,0) && 
-		 G.mark(e1,1)==G.mark(e2,1)); }
+{ 
+  CGAL_USE(e1);
+  CGAL_USE(e2);
+  CGAL_assertion(G.mark(e1,0)==G.mark(e2,0) && 
+		 G.mark(e1,1)==G.mark(e2,1)); 
+}
 
 void discard_info(Halfedge_handle e) const 
 { G.discard_info(e); }
diff --git a/OpenNL/include/CGAL/OpenNL/linear_solver.h b/OpenNL/include/CGAL/OpenNL/linear_solver.h
index a245424dd6b..80f6895aba3 100644
--- a/OpenNL/include/CGAL/OpenNL/linear_solver.h
+++ b/OpenNL/include/CGAL/OpenNL/linear_solver.h
@@ -49,6 +49,8 @@
 #include <iostream>
 #include <cstdlib>
 
+#include <CGAL/use.h>
+
 namespace OpenNL {
 
 
@@ -436,6 +438,7 @@ protected:
     }
 
     void check_state(State s) {
+            CGAL_USE(s);
             CGAL_assertion(state_ == s) ;
     }