diff --git a/Interval_arithmetic/include/CGAL/Static_filters/Side_of_oriented_sphere_3.h b/Interval_arithmetic/include/CGAL/Static_filters/Side_of_oriented_sphere_3.h
index af92b845fa7..d696555a2c2 100644
--- a/Interval_arithmetic/include/CGAL/Static_filters/Side_of_oriented_sphere_3.h
+++ b/Interval_arithmetic/include/CGAL/Static_filters/Side_of_oriented_sphere_3.h
@@ -44,6 +44,8 @@ public:
   {
       CGAL_PROFILER("In_sphere_3 calls");
 
+      using std::fabs;
+
       double px, py, pz, qx, qy, qz, rx, ry, rz, sx, sy, sz, tx, ty, tz;
 
       if (fit_in_double(p.x(), px) && fit_in_double(p.y(), py) &&
diff --git a/Interval_arithmetic/test/Interval_arithmetic/Static_filters.C b/Interval_arithmetic/test/Interval_arithmetic/Static_filters.C
index 356e5cbce6f..db2afe05860 100644
--- a/Interval_arithmetic/test/Interval_arithmetic/Static_filters.C
+++ b/Interval_arithmetic/test/Interval_arithmetic/Static_filters.C
@@ -257,9 +257,9 @@ int main(int argc, char **argv)
 {
   // CGAL::force_ieee_double_precision();
 
-  int loops = (argc < 2) ? 2000 : atoi(argv[1]);
+  int loops = (argc < 2) ? 2000 : std::atoi(argv[1]);
   int seed  = (argc < 3) ? CGAL::default_random.get_int(0, 1<<30)
-                         : atoi(argv[2]);
+                         : std::atoi(argv[2]);
 
   std::cout << "Initializing random generator with seed = " << seed
             << std::endl
diff --git a/Inventor/include/CGAL/IO/VRML_2_ostream.h b/Inventor/include/CGAL/IO/VRML_2_ostream.h
index 3f76db5a67e..65821ddda7a 100644
--- a/Inventor/include/CGAL/IO/VRML_2_ostream.h
+++ b/Inventor/include/CGAL/IO/VRML_2_ostream.h
@@ -309,7 +309,7 @@ operator<<(VRML_2_ostream& os,
              "                    geometry\n"
              "                        Sphere { "
              "radius ";
-  os <<      ::sqrt(CGAL::to_double(s.squared_radius())) <<" }\n";
+  os <<      std::sqrt(CGAL::to_double(s.squared_radius())) <<" }\n";
   os <<      "                } #children Shape\n"
              "              } # Transform\n"
              "            ] #children\n"