diff --git a/.travis.yml b/.travis.yml
index ef80008ff65..5d567fb302e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,58 +1,104 @@
 language: cpp 
 dist: trusty 
 sudo: required 
-env: 
- matrix: 
-  - PACKAGE='CHECK' 
-  - PACKAGE='AABB_tree Advancing_front_surface_reconstruction Algebraic_foundations ' 
-  - PACKAGE='Algebraic_kernel_d Algebraic_kernel_for_circles Algebraic_kernel_for_spheres ' 
-  - PACKAGE='Alpha_shapes_2 Alpha_shapes_3 Apollonius_graph_2 ' 
-  - PACKAGE='Arithmetic_kernel Arrangement_on_surface_2 Barycentric_coordinates_2 ' 
-  - PACKAGE='BGL Boolean_set_operations_2 Bounding_volumes ' 
-  - PACKAGE='Box_intersection_d Cartesian_kernel CGAL_Core ' 
-  - PACKAGE='CGAL_ImageIO CGAL_ipelets Circular_kernel_2 ' 
-  - PACKAGE='Circular_kernel_3 Circulator Classification ' 
-  - PACKAGE='Combinatorial_map Cone_spanners_2 Convex_decomposition_3 ' 
-  - PACKAGE='Convex_hull_2 Convex_hull_3 Convex_hull_d ' 
-  - PACKAGE='Distance_2 Distance_3 Envelope_2 ' 
-  - PACKAGE='Envelope_3 Filtered_kernel Generalized_map ' 
-  - PACKAGE='Generator Geomview GraphicsView ' 
-  - PACKAGE='HalfedgeDS Hash_map Homogeneous_kernel ' 
-  - PACKAGE='Inscribed_areas Installation Interpolation ' 
-  - PACKAGE='Intersections_2 Intersections_3 Interval_skip_list ' 
-  - PACKAGE='Interval_support Inventor Jet_fitting_3 ' 
-  - PACKAGE='Kernel_23 Kernel_d Kinetic_data_structures ' 
-  - PACKAGE='Kinetic_framework LEDA Linear_cell_complex ' 
-  - PACKAGE='MacOSX Maintenance Matrix_search ' 
-  - PACKAGE='Mesh_2 Mesh_3 Mesher_level ' 
-  - PACKAGE='Minkowski_sum_2 Minkowski_sum_3 Modifier ' 
-  - PACKAGE='Modular_arithmetic Nef_2 Nef_3 ' 
-  - PACKAGE='Nef_S2 NewKernel_d Number_types ' 
-  - PACKAGE='OpenNL Operations_on_polyhedra Optimal_transportation_reconstruction_2 ' 
-  - PACKAGE='Optimisation_basic Partition_2 Periodic_2_triangulation_2 ' 
-  - PACKAGE='Periodic_3_triangulation_3 Point_set_2 Point_set_3 ' 
-  - PACKAGE='Point_set_processing_3 Point_set_shape_detection_3 Poisson_surface_reconstruction_3 ' 
-  - PACKAGE='Polygon Polygon_mesh_processing Polyhedron ' 
-  - PACKAGE='Polyhedron_IO Polyline_simplification_2 Polynomial ' 
-  - PACKAGE='Polytope_distance_d Principal_component_analysis Principal_component_analysis_LGPL ' 
-  - PACKAGE='Profiling_tools Property_map QP_solver ' 
-  - PACKAGE='Random_numbers Ridges_3 Scale_space_reconstruction_3 ' 
-  - PACKAGE='Scripts SearchStructures Segment_Delaunay_graph_2 ' 
-  - PACKAGE='Segment_Delaunay_graph_Linf_2 Set_movable_separability_2 Skin_surface_3 ' 
-  - PACKAGE='Snap_rounding_2 Solver_interface Spatial_searching ' 
-  - PACKAGE='Spatial_sorting STL_Extension Straight_skeleton_2 ' 
-  - PACKAGE='Stream_lines_2 Stream_support Subdivision_method_3 ' 
-  - PACKAGE='Surface_mesh Surface_mesh_deformation Surface_mesher ' 
-  - PACKAGE='Surface_mesh_parameterization Surface_mesh_segmentation Surface_mesh_shortest_path ' 
-  - PACKAGE='Surface_mesh_simplification Surface_mesh_skeletonization Surface_sweep_2 ' 
-  - PACKAGE='TDS_2 TDS_3 Testsuite ' 
-  - PACKAGE='Three Triangulation Triangulation_2 ' 
-  - PACKAGE='Triangulation_3 Union_find Visibility_2 ' 
-  - PACKAGE='Voronoi_diagram_2 wininst ' 
-  - PACKAGE='Polyhedron_demo' 
-compiler: 
-  - clang-3.6
-  - gcc  
+matrix:
+ include: 
+  - compiler: gcc 
+    env: PACKAGE='CHECK' 
+  - compiler: clang-3.6
+    env: PACKAGE='CHECK' 
+  - compiler: clang-3.6
+    env: PACKAGE='AABB_tree Advancing_front_surface_reconstruction Algebraic_foundations ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Algebraic_kernel_d Algebraic_kernel_for_circles Algebraic_kernel_for_spheres ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Alpha_shapes_2 Alpha_shapes_3 Apollonius_graph_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Arithmetic_kernel Arrangement_on_surface_2 Barycentric_coordinates_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='BGL Boolean_set_operations_2 Bounding_volumes ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Box_intersection_d Cartesian_kernel CGAL_Core ' 
+  - compiler: clang-3.6
+    env: PACKAGE='CGAL_ImageIO CGAL_ipelets Circular_kernel_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Circular_kernel_3 Circulator Classification ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Combinatorial_map Cone_spanners_2 Convex_decomposition_3 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Convex_hull_2 Convex_hull_3 Convex_hull_d ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Distance_2 Distance_3 Envelope_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Envelope_3 Filtered_kernel Generalized_map ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Generator Geomview GraphicsView ' 
+  - compiler: clang-3.6
+    env: PACKAGE='HalfedgeDS Hash_map Homogeneous_kernel ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Inscribed_areas Installation Interpolation ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Intersections_2 Intersections_3 Interval_skip_list ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Interval_support Inventor Jet_fitting_3 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Kernel_23 Kernel_d Kinetic_data_structures ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Kinetic_framework LEDA Linear_cell_complex ' 
+  - compiler: clang-3.6
+    env: PACKAGE='MacOSX Maintenance Matrix_search ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Mesh_2 Mesh_3 Mesher_level ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Minkowski_sum_2 Minkowski_sum_3 Modifier ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Modular_arithmetic Nef_2 Nef_3 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Nef_S2 NewKernel_d Number_types ' 
+  - compiler: clang-3.6
+    env: PACKAGE='OpenNL Operations_on_polyhedra Optimal_transportation_reconstruction_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Optimisation_basic Partition_2 Periodic_2_triangulation_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Periodic_3_triangulation_3 Point_set_2 Point_set_3 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Point_set_processing_3 Point_set_shape_detection_3 Poisson_surface_reconstruction_3 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Polygon Polygon_mesh_processing Polyhedron ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Polyhedron_IO Polyline_simplification_2 Polynomial ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Polytope_distance_d Principal_component_analysis Principal_component_analysis_LGPL ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Profiling_tools Property_map QP_solver ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Random_numbers Ridges_3 Scale_space_reconstruction_3 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Scripts SearchStructures Segment_Delaunay_graph_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Segment_Delaunay_graph_Linf_2 Set_movable_separability_2 Skin_surface_3 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Snap_rounding_2 Solver_interface Spatial_searching ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Spatial_sorting STL_Extension Straight_skeleton_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Stream_lines_2 Stream_support Subdivision_method_3 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Surface_mesh Surface_mesh_deformation Surface_mesher ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Surface_mesh_parameterization Surface_mesh_segmentation Surface_mesh_shortest_path ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Surface_mesh_simplification Surface_mesh_skeletonization Surface_sweep_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='TDS_2 TDS_3 Testsuite ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Three Triangulation Triangulation_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Triangulation_3 Union_find Visibility_2 ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Voronoi_diagram_2 wininst ' 
+  - compiler: clang-3.6
+    env: PACKAGE='Polyhedron_demo' 
 install: 
   - if [[ "$CXX" = "clang++" ]]; then export CXX=clang++-3.6 CC=clang-3.6; fi
 before_script: 
diff --git a/.travis/generate_travis.sh b/.travis/generate_travis.sh
index 50e4e9865b0..7c65175182b 100755
--- a/.travis/generate_travis.sh
+++ b/.travis/generate_travis.sh
@@ -41,27 +41,32 @@ old_IFS=$IFS
 IFS=$'\n'
 for LINE in $(cat "$PWD/.travis/template.txt")
 do
-	if [ "$LINE" != " matrix: " ]
+	if [ "$LINE" != " include:" ]
 	then
 		echo "$LINE" >> .travis.yml
   else
   	break
 	fi
 done
-echo " matrix: " >> .travis.yml
+echo " include: " >> .travis.yml
 #writes the matrix
-echo "  - PACKAGE='CHECK' " >> .travis.yml
+echo "  - compiler: gcc " >> .travis.yml
+echo "    env: PACKAGE='CHECK' " >> .travis.yml
+echo "  - compiler: clang-3.6" >> .travis.yml
+echo "    env: PACKAGE='CHECK' " >> .travis.yml
 for package in ${PACKAGES[@]}
 do
- 	echo "  - PACKAGE='$package' " >> .travis.yml
+echo "  - compiler: clang-3.6" >> .travis.yml
+echo "    env: PACKAGE='$package' " >> .travis.yml
 done
-echo "  - PACKAGE='Polyhedron_demo' " >> .travis.yml
+echo "  - compiler: clang-3.6" >> .travis.yml
+echo "    env: PACKAGE='Polyhedron_demo' " >> .travis.yml
 
 #writes the end of the file
 COPY=0
 for LINE in $(cat "$PWD/.travis/template.txt")
 do
-	if [ "$LINE" = "compiler: " ]
+	if [ "$LINE" = "install: " ]
 	then
 		COPY=1
 	fi
diff --git a/.travis/template.txt b/.travis/template.txt
index c48cb2c88a9..f01813ad1d7 100644
--- a/.travis/template.txt
+++ b/.travis/template.txt
@@ -1,12 +1,9 @@
 language: cpp 
 dist: trusty 
 sudo: required 
-env: 
- matrix: 
+matrix:
+ include:
   PACKAGES_MATRIX
-compiler: 
-  - clang-3.6
-  - gcc  
 install: 
   - if [[ "$CXX" = "clang++" ]]; then export CXX=clang++-3.6 CC=clang-3.6; fi