diff --git a/Hyperbolic_triangulation_2/include/CGAL/Hyperbolic_Delaunay_triangulation_2.h b/Hyperbolic_triangulation_2/include/CGAL/Hyperbolic_Delaunay_triangulation_2.h
index adfb51314c0..ab4e6c1835b 100644
--- a/Hyperbolic_triangulation_2/include/CGAL/Hyperbolic_Delaunay_triangulation_2.h
+++ b/Hyperbolic_triangulation_2/include/CGAL/Hyperbolic_Delaunay_triangulation_2.h
@@ -484,7 +484,7 @@ public:
 
     if (dim_was_2) 
     {
-      for (int i = 0; i < nbr.size(); ++i) 
+      for (unsigned int i = 0; i < nbr.size(); ++i) 
       {
         mark_star_faces(nbr[i]);
         ensure_hyperbolic_face_handle(nbr[i]);
@@ -670,8 +670,7 @@ private:
   {
     if(const Face_data* td = object_cast<Face_data>(&f->tds_data()))
     {
-      Face_data fd = object_cast<Face_data>(f->tds_data());
-      return !fd.get_is_Delaunay_hyperbolic();
+      return !td->get_is_Delaunay_hyperbolic();
     }
     else
     {
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 419d1754dca..7a7a742d678 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
@@ -146,20 +146,20 @@ public:
     std::vector<Matrix> gens;
     T::Hyperbolic_translation::generators(gens);
     std::vector<Matrix> tmp;
-    for(int j=0; j<gens.size(); ++j) {
+    for(unsigned int j=0; j<gens.size(); ++j) {
       tmp.push_back(gens[j]);
     }
 
     for(int j=0; j<3; ++j) {
-      int N = tmp.size();
-      for(int i=0; i<N; ++i) {
-        for(int k=0; k< gens.size(); k++) {
+      std::size_t N = tmp.size();
+      for(unsigned int i=0; i<N; ++i) {
+        for(unsigned int k=0; k< gens.size(); k++) {
           tmp.push_back(gens[k]*tmp[i]);
         }
       }
     }
 
-    for(int k=0; k< tmp.size(); k++) {
+    for(unsigned int k=0; k< tmp.size(); k++) {
       if(std::find(trans.begin(), trans.end(), tmp[k]) == trans.end()) {
         trans.push_back(tmp[k]);
       }
@@ -332,7 +332,7 @@ TriangulationGraphicsItem<T>::drawAll(QPainter *painter)
       //   std::cout << "painting copies" << std::endl;
       //   typename Geom_traits::Point_2 pts[] = {fit->translation(Triangulation_cw_ccw_2::ccw(0)).apply(fit->vertex(Triangulation_cw_ccw_2::ccw(k))->point());
       //   typename Geom_traits::Point_2 tgt = fit->translation(Triangulation_cw_ccw_2::cw(k)).apply(fit->vertex(Triangulation_cw_ccw_2::cw(k))->point());
-        for(int j=0; j<trans.size(); ++j) {
+        for(unsigned int j=0; j<trans.size(); ++j) {
           painterostream << t->construct_hyperbolic_segment( CP2()(pts[0], trans[j]), CP2()(pts[1], trans[j]) );
           painterostream << t->construct_hyperbolic_segment( CP2()(pts[1], trans[j]), CP2()(pts[2], trans[j]) );
           painterostream << t->construct_hyperbolic_segment( CP2()(pts[2], trans[j]), CP2()(pts[0], trans[j]) );
@@ -397,7 +397,7 @@ TriangulationGraphicsItem<T>::paintVertices(QPainter *painter)
       painter->drawPoint(point);
       
       if(visible_copies) {
-        for(int k=0; k< trans.size(); k++) {
+        for(unsigned int k=0; k< trans.size(); k++) {
           typedef typename Geom_traits::Construct_hyperbolic_point_2 CP2;
           typename Geom_traits::Point_2 img = CP2()(it->point(), trans[k]);
 
diff --git a/Periodic_4_hyperbolic_triangulation_2/demo/Periodic_4_hyperbolic_triangulation_2/include/internal/hyperbolic_free_motion_animation.h b/Periodic_4_hyperbolic_triangulation_2/demo/Periodic_4_hyperbolic_triangulation_2/include/internal/hyperbolic_free_motion_animation.h
index 47d35cc94b8..e99bda024fd 100644
--- a/Periodic_4_hyperbolic_triangulation_2/demo/Periodic_4_hyperbolic_triangulation_2/include/internal/hyperbolic_free_motion_animation.h
+++ b/Periodic_4_hyperbolic_triangulation_2/demo/Periodic_4_hyperbolic_triangulation_2/include/internal/hyperbolic_free_motion_animation.h
@@ -205,7 +205,7 @@ MainWindow::animate() {
     //std::cout << "  ..checking generators "; std::cout.flush();
     std::vector<Hyperbolic_translation> gens;
     Hyperbolic_translation::generators(gens);
-    for(int i=0; i<gens.size(); ++i) {
+    for(unsigned int i=0; i<gens.size(); ++i) {
       o = gens[i];
       if(check(dt.construct_point(p,o)) == CGAL::ON_BOUNDED_SIDE) {
         found = true;
@@ -222,7 +222,7 @@ MainWindow::animate() {
     if(!found) {
       std::vector<Hyperbolic_translation> tr;
       get_all_translations(tr);
-      for(int i=0; i<tr.size(); ++i) {
+      for(unsigned int i=0; i<tr.size(); ++i) {
         o = tr[i];
         if(check(dt.construct_point(p,o)) == CGAL::ON_BOUNDED_SIDE) {
           found = true;