diff --git a/HydroGrid.py b/HydroGrid.py
index 723bef7345889ef576f02c43bd4d42d9d25954a8..bb60548593daa8a9badac94c51aa1671d038983f 100644
--- a/HydroGrid.py
+++ b/HydroGrid.py
@@ -39,7 +39,7 @@ def corners(lon, lat) :
     for i in range(iim) :
         for j in range(jjm) :
             #
-            boxll = RPP.boxit([lon[j,i], lat[j,i]], hdlon, hdlat, 4)
+            boxll = RPP.boxit([lon[j,i], lat[j,i]], hdlon, hdlat, 2)
             #
             cornerspoly.append(polygon.SphericalPolygon.from_lonlat([p[0] for p in boxll], [p[1] for p in boxll], center=[lon[j,i], lat[j,i]]))
             #