--- a/src/uan/examples/uan-cw-example.cc	Fri Aug 31 12:24:28 2012 +0200
+++ b/src/uan/examples/uan-cw-example.cc	Sat Sep 01 20:57:21 2012 +0200
@@ -159,7 +159,7 @@
       {
         double x = urv->GetValue (0, m_boundary);
         double y = urv->GetValue (0, m_boundary);
-        double newr = sqrt ((x - m_boundary / 2.0) * (x - m_boundary / 2.0)
+        double newr = std::sqrt ((x - m_boundary / 2.0) * (x - m_boundary / 2.0)
                             + (y - m_boundary / 2.0) * (y - m_boundary / 2.0));
         rsum += newr;
         minr = std::min (minr, newr);