diff --git a/zobov/vozutil.c b/zobov/vozutil.c
index aba81e2..c56da6f 100644
--- a/zobov/vozutil.c
+++ b/zobov/vozutil.c
@@ -46,7 +46,7 @@ int delaunadj (coordT *points, int nvp, int nvpbuf, int nvpall, PARTADJ **adjs)
   }
 
   /* Delaunay triangulation*/
-  sprintf (flags, "qhull s d QJ");
+  sprintf (flags, "qhull s d Qt");
   exitcode= qh_new_qhull (dim, nvpall, points, ismalloc,
                       flags, outfile, errfile);