diff --git a/AABB_tree/demo/AABB_tree/Viewer.cpp b/AABB_tree/demo/AABB_tree/Viewer.cpp
index 2f411def1df..35b2496a69f 100644
--- a/AABB_tree/demo/AABB_tree/Viewer.cpp
+++ b/AABB_tree/demo/AABB_tree/Viewer.cpp
@@ -5,7 +5,7 @@
 #include <CGAL/Qt/CreateOpenGLContext.h>
 
 Viewer::Viewer(QWidget* parent)
-  : QGLViewer(CGAL::Qt::createOpenGLContext(),parent),
+  : QGLViewer(CGAL::Qt::createOpenGLContext(parent),parent),
     m_pScene(NULL),
     m_custom_mouse(false)
 {
diff --git a/Alpha_shapes_3/demo/Alpha_shapes_3/Viewer.cpp b/Alpha_shapes_3/demo/Alpha_shapes_3/Viewer.cpp
index a5a0dd2f222..e1f2e029a66 100644
--- a/Alpha_shapes_3/demo/Alpha_shapes_3/Viewer.cpp
+++ b/Alpha_shapes_3/demo/Alpha_shapes_3/Viewer.cpp
@@ -5,7 +5,7 @@
 #include "CGAL/Qt/CreateOpenGLContext.h"
 
 Viewer::Viewer(QWidget* parent)
-  : QGLViewer(CGAL::Qt::createOpenGLContext(),parent)
+  : QGLViewer(CGAL::Qt::createOpenGLContext(parent),parent)
 {
   are_buffers_initialized = false;
 }
diff --git a/Circular_kernel_3/demo/Circular_kernel_3/Viewer.cpp b/Circular_kernel_3/demo/Circular_kernel_3/Viewer.cpp
index 0036038b6de..413cbeca0e8 100644
--- a/Circular_kernel_3/demo/Circular_kernel_3/Viewer.cpp
+++ b/Circular_kernel_3/demo/Circular_kernel_3/Viewer.cpp
@@ -7,7 +7,7 @@
 
 
 Viewer::Viewer(QWidget* parent )
-  : QGLViewer(CGAL::Qt::createOpenGLContext(),parent)
+  : QGLViewer(CGAL::Qt::createOpenGLContext(parent),parent)
 {
     extension_is_found = false;
 }
diff --git a/GraphicsView/include/CGAL/Qt/CreateOpenGLContext.h b/GraphicsView/include/CGAL/Qt/CreateOpenGLContext.h
index 48799048e41..d05c5904cc6 100644
--- a/GraphicsView/include/CGAL/Qt/CreateOpenGLContext.h
+++ b/GraphicsView/include/CGAL/Qt/CreateOpenGLContext.h
@@ -23,9 +23,9 @@
 #include <QGLContext>
 namespace CGAL{
 namespace Qt{
-inline QGLContext* createOpenGLContext()
+inline QGLContext* createOpenGLContext(QObject* parent)
 {
-    QOpenGLContext *context = new QOpenGLContext();
+    QOpenGLContext *context = new QOpenGLContext(parent);
     QSurfaceFormat format;
     format.setVersion(2,1);
     format.setProfile(QSurfaceFormat::CompatibilityProfile);
@@ -35,9 +35,9 @@ inline QGLContext* createOpenGLContext()
     return result;
 }
 
-inline QGLContext* createOpenGLMSAAContext()
+inline QGLContext* createOpenGLMSAAContext(QObject* parent)
 {
-    QOpenGLContext *context = new QOpenGLContext();
+    QOpenGLContext *context = new QOpenGLContext(parent);
     QSurfaceFormat format;
     format.setVersion(2,1);
     format.setProfile(QSurfaceFormat::CompatibilityProfile);
diff --git a/Linear_cell_complex/demo/Linear_cell_complex/Viewer.cpp b/Linear_cell_complex/demo/Linear_cell_complex/Viewer.cpp
index dca13ab0f40..052dda15a5b 100644
--- a/Linear_cell_complex/demo/Linear_cell_complex/Viewer.cpp
+++ b/Linear_cell_complex/demo/Linear_cell_complex/Viewer.cpp
@@ -28,7 +28,7 @@
 #include <QDebug>
 
 Viewer::Viewer(QWidget* parent)
-  : QGLViewer(CGAL::Qt::createOpenGLMSAAContext(),parent), wireframe(false),
+  : QGLViewer(CGAL::Qt::createOpenGLMSAAContext(parent),parent), wireframe(false),
     flatShading(true), edges(true), vertices(true),
     m_previous_scene_empty(true), are_buffers_initialized(false)
 {
diff --git a/Linear_cell_complex/examples/Linear_cell_complex/CMakeLists.txt b/Linear_cell_complex/examples/Linear_cell_complex/CMakeLists.txt
index 390519eb032..9556c4f4bb6 100644
--- a/Linear_cell_complex/examples/Linear_cell_complex/CMakeLists.txt
+++ b/Linear_cell_complex/examples/Linear_cell_complex/CMakeLists.txt
@@ -11,11 +11,11 @@ endif()
 # If you want to visualize a linear cell complex, you can use the following viewer
 # based on qt. Just uncomment the following two lines, plus the lines qt5_use_modules below
 
-# find_package(CGAL COMPONENTS Qt5)
-# include("CMakeLCCViewerQt.inc")
+ find_package(CGAL COMPONENTS Qt5)
+ include("CMakeLCCViewerQt.inc")
 
 # If you don't want to visualize, use the following line (otherwise comment it)
-find_package(CGAL QUIET COMPONENTS Core)
+#find_package(CGAL QUIET COMPONENTS Core)
 
 # For Gprof.
 # ADD_DEFINITIONS("-pg")
@@ -43,12 +43,12 @@ if ( CGAL_FOUND )
   add_executable(voronoi_2 voronoi_2.cpp)
   target_link_libraries(voronoi_2 ${CGAL_LIBRARIES} ${CGAL_3RD_PARTY_LIBRARIES}
                                   ${MAP_VIEWER_LIBRARIES})
-  # qt5_use_modules(voronoi_2 ${MAP_VIEWER_MODULES})
+   qt5_use_modules(voronoi_2 ${MAP_VIEWER_MODULES})
 
   add_executable(voronoi_3 voronoi_3.cpp)
   target_link_libraries(voronoi_3 ${CGAL_LIBRARIES} ${CGAL_3RD_PARTY_LIBRARIES}
                                   ${MAP_VIEWER_LIBRARIES})
-  # qt5_use_modules(voronoi_3 ${MAP_VIEWER_MODULES})
+   qt5_use_modules(voronoi_3 ${MAP_VIEWER_MODULES})
 
 else()
 
diff --git a/Linear_cell_complex/examples/Linear_cell_complex/linear_cell_complex_3_viewer_qt.h b/Linear_cell_complex/examples/Linear_cell_complex/linear_cell_complex_3_viewer_qt.h
index ed390cf7cd8..10418b03a50 100644
--- a/Linear_cell_complex/examples/Linear_cell_complex/linear_cell_complex_3_viewer_qt.h
+++ b/Linear_cell_complex/examples/Linear_cell_complex/linear_cell_complex_3_viewer_qt.h
@@ -154,7 +154,7 @@ class SimpleLCCViewerQt : public QGLViewer, public QOpenGLFunctions_2_1
 public:
   // Constructor/Destructor
   SimpleLCCViewerQt(LCC& alcc) :
-    QGLViewer(CGAL::Qt::createOpenGLContext()),
+    QGLViewer(CGAL::Qt::createOpenGLContext(0)),
     lcc(alcc),
     wireframe(false),
     flatShading(true),
diff --git a/Mesh_3/demo/Mesh_3/src/CGAL_demo/Viewer.cpp b/Mesh_3/demo/Mesh_3/src/CGAL_demo/Viewer.cpp
index 908ed02fc38..5df0afa2a13 100644
--- a/Mesh_3/demo/Mesh_3/src/CGAL_demo/Viewer.cpp
+++ b/Mesh_3/demo/Mesh_3/src/CGAL_demo/Viewer.cpp
@@ -3,7 +3,7 @@
 #include <CGAL/Qt/CreateOpenGLContext.h>
 
 Viewer::Viewer(QWidget* parent, bool antialiasing)
-  : QGLViewer(CGAL::Qt::createOpenGLContext(), parent),
+  : QGLViewer(CGAL::Qt::createOpenGLContext(parent), parent),
     scene(0),
     antialiasing(antialiasing),
     twosides(false),
diff --git a/Periodic_3_triangulation_3/demo/Periodic_3_triangulation_3/Viewer.cpp b/Periodic_3_triangulation_3/demo/Periodic_3_triangulation_3/Viewer.cpp
index 51521874203..ebb98bb5238 100644
--- a/Periodic_3_triangulation_3/demo/Periodic_3_triangulation_3/Viewer.cpp
+++ b/Periodic_3_triangulation_3/demo/Periodic_3_triangulation_3/Viewer.cpp
@@ -2,7 +2,7 @@
  #include <CGAL/Qt/CreateOpenGLContext.h>
 
 Viewer::Viewer(QWidget *parent)
-: QGLViewer(CGAL::Qt::createOpenGLContext(),parent)
+: QGLViewer(CGAL::Qt::createOpenGLContext(parent),parent)
 {}
 Viewer::~Viewer()
 {}
diff --git a/Periodic_3_triangulation_3/demo/Periodic_Lloyd_3/Viewer.h b/Periodic_3_triangulation_3/demo/Periodic_Lloyd_3/Viewer.h
index c03df5c5c65..bf2fc24c863 100644
--- a/Periodic_3_triangulation_3/demo/Periodic_Lloyd_3/Viewer.h
+++ b/Periodic_3_triangulation_3/demo/Periodic_Lloyd_3/Viewer.h
@@ -22,7 +22,7 @@ class Viewer : public QGLViewer, QOpenGLFunctions_2_1 {
   int nr_of_facets;
 public:
   Viewer(QWidget* parent)
-    : QGLViewer(CGAL::Qt::createOpenGLContext(), parent)
+    : QGLViewer(CGAL::Qt::createOpenGLContext(parent), parent)
   {}
   ~Viewer()
   {
diff --git a/Three/include/CGAL/Three/Viewer_interface.h b/Three/include/CGAL/Three/Viewer_interface.h
index e99b5bbd785..d6e0a2ca4b7 100644
--- a/Three/include/CGAL/Three/Viewer_interface.h
+++ b/Three/include/CGAL/Three/Viewer_interface.h
@@ -64,7 +64,7 @@ public:
    NB_OF_PROGRAMS               /** Holds the number of different programs in this enum.*/
   };
 
-  Viewer_interface(QWidget* parent) : QGLViewer(CGAL::Qt::createOpenGLContext(), parent) {}
+  Viewer_interface(QWidget* parent) : QGLViewer(CGAL::Qt::createOpenGLContext(parent), parent) {}
   virtual ~Viewer_interface() {}
 
   //! Sets the scene for the viewer.
diff --git a/Triangulation_3/demo/Triangulation_3/Viewer.h b/Triangulation_3/demo/Triangulation_3/Viewer.h
index c865f018a41..ca4362ec0c7 100644
--- a/Triangulation_3/demo/Triangulation_3/Viewer.h
+++ b/Triangulation_3/demo/Triangulation_3/Viewer.h
@@ -24,7 +24,7 @@ class Viewer : public QGLViewer, QOpenGLFunctions_2_1 {
 
 public:
   Viewer(QWidget* parent)
-    : QGLViewer(CGAL::Qt::createOpenGLContext(),parent)
+    : QGLViewer(CGAL::Qt::createOpenGLContext(parent),parent)
     , m_showAxis(false)
     , m_showVertex(true)
     , m_showDEdge(true)