diff --git a/Hyperbolic_triangulation_2/demo/Hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItem.h b/Hyperbolic_triangulation_2/demo/Hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItem.h
index 22d185807c5..5dc2f7364a7 100644
--- a/Hyperbolic_triangulation_2/demo/Hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItem.h
+++ b/Hyperbolic_triangulation_2/demo/Hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItem.h
@@ -174,8 +174,8 @@ TriangulationGraphicsItem<T>::paintVertices(QPainter *painter)
     Converter<Geom_traits> convert;
 
     painter->setPen(vertices_pen);
-    QMatrix matrix = painter->matrix();
-    painter->resetMatrix();
+    QTransform matrix = painter->worldTransform();
+    painter->resetTransform();
     for(typename T::All_vertices_iterator it = t->all_vertices_begin();
         it != t->all_vertices_end();
         it++){
@@ -191,10 +191,10 @@ TriangulationGraphicsItem<T>::paintVertex(typename T::Vertex_handle vh)
 {
   Converter<Geom_traits> convert;
   m_painter->setPen(vertices_pen);
-  QMatrix matrix = m_painter->matrix();
-  m_painter->resetMatrix();
+  QTransform matrix = m_painter->worldTransform();
+  m_painter->resetTransform();
   m_painter->drawPoint(matrix.map(convert(t->point(vh))));
-  m_painter->setMatrix(matrix);
+  m_painter->setWorldTransform(matrix);
 }
 
 template <typename T>
diff --git a/Hyperbolic_triangulation_2/demo/Hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItemWithColorInfo.h b/Hyperbolic_triangulation_2/demo/Hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItemWithColorInfo.h
index d5d12cf31d4..0ab303ce31f 100644
--- a/Hyperbolic_triangulation_2/demo/Hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItemWithColorInfo.h
+++ b/Hyperbolic_triangulation_2/demo/Hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItemWithColorInfo.h
@@ -196,8 +196,8 @@ TriangulationGraphicsItem<T>::paintVertices(QPainter *painter)
     Converter<Geom_traits> convert;
 
     painter->setPen(verticesPen());
-    QMatrix matrix = painter->matrix();
-    painter->resetMatrix();
+    QTransform matrix = painter->worldTransform();
+    painter->resetTransform();
     for(typename T::Finite_vertices_iterator it = t->finite_vertices_begin();
         it != t->finite_vertices_end();
         it++){
@@ -311,10 +311,10 @@ TriangulationGraphicsItem<T>::paintOneVertex(const typename T::Point& point)
   Converter<Geom_traits> convert;
 
   m_painter->setPen(this->verticesPen());
-  QMatrix matrix = m_painter->matrix();
-  m_painter->resetMatrix();
+  QTransform matrix = m_painter->worldTransform();
+  m_painter->resetTransform();
   m_painter->drawPoint(matrix.map(convert(point)));
-  m_painter->setMatrix(matrix);
+  m_painter->setWorldTransform(matrix);
 }
 
 template <typename T>
@@ -324,10 +324,10 @@ TriangulationGraphicsItem<T>::paintVertex(typename T::Vertex_handle vh)
   Converter<Geom_traits> convert;
   m_painter->setPen(this->verticesPen());
   
-  QMatrix matrix = m_painter->matrix();
-  m_painter->resetMatrix();
+  QTransform matrix = m_painter->worldTransform();
+  m_painter->resetTransform();
   m_painter->drawPoint(matrix.map(convert(t->point(vh))));
-  m_painter->setMatrix(matrix);
+  m_painter->setWorldTransform(matrix);
 }
 
 template <typename T>
diff --git a/Periodic_4_hyperbolic_triangulation_2/demo/Periodic_4_hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItem.h b/Periodic_4_hyperbolic_triangulation_2/demo/Periodic_4_hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItem.h
index 7a7a742d678..e323f616cee 100644
--- a/Periodic_4_hyperbolic_triangulation_2/demo/Periodic_4_hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItem.h
+++ b/Periodic_4_hyperbolic_triangulation_2/demo/Periodic_4_hyperbolic_triangulation_2/include/internal/Qt/TriangulationGraphicsItem.h
@@ -365,10 +365,10 @@ TriangulationGraphicsItem<T>::paintVertices(QPainter *painter)
     Converter<Geom_traits> convert;
 
     painter->setPen(verticesPen());
-    QMatrix matrix = painter->matrix();
+    QTransform matrix = painter->worldTransform();
     //QMatrix tr(1, 0, 0, -1, 0, 0);
     //matrix = tr*matrix;
-    painter->resetMatrix();
+    painter->resetTransform();
 
     QPen temp = painter->pen();
     QPen old = temp;
@@ -455,10 +455,10 @@ TriangulationGraphicsItem<T>::paintOneVertex(const typename T::Point& point)
   Converter<Geom_traits> convert;
 
   m_painter->setPen(this->verticesPen());
-  QMatrix matrix = m_painter->matrix();
-  m_painter->resetMatrix();
+  QTransform matrix = m_painter->worldTransform();
+  m_painter->resetTransform();
   m_painter->drawPoint(matrix.map(convert(point)));
-  m_painter->setMatrix(matrix);
+  m_painter->setWorldTransform(matrix);
 }
 
 template <typename T>
@@ -468,10 +468,10 @@ TriangulationGraphicsItem<T>::paintVertex(typename T::Vertex_handle vh)
   Converter<Geom_traits> convert;
   m_painter->setPen(this->verticesPen());
   
-  QMatrix matrix = m_painter->matrix();
-  m_painter->resetMatrix();
+  QTransform matrix = m_painter->worldTransform();
+  m_painter->resetTransform();
   m_painter->drawPoint(matrix.map(convert(vh->point())));
-  m_painter->setMatrix(matrix);
+  m_painter->setWorldTransform(matrix);
 }
 
 template <typename T>