diff --git a/phy_export.py b/phy_export.py
index 9576143..bea02b2 100644
--- a/phy_export.py
+++ b/phy_export.py
@@ -22,15 +22,16 @@ def write(filename):
             elif len(ob.data.faces) == 6:
                 # found a cube
                 e = ob.getEuler()
+                size = ob.getSize()
                 out.write("cube \"%s\" %f %f %f  %f %f %f  %f %f %f\n" %
-                        ((ob.name,) + ob.getSize() +
+                        ((ob.name,2*size[0],2*size[1],2*size[2]) +
                             ob.getLocation() +
                             (e[0], e[1], e[2])))
             elif len(ob.data.faces) < 256:
                 # found a cylinder
                 e = ob.getEuler()
                 out.write("cylinder \"%s\" %f %f  %f %f %f  %f %f %f\n" %
-                        ((ob.name,) + (ob.getSize()[0], ob.getSize()[2]) +
+                        ((ob.name,) + (ob.getSize()[0], ob.getSize()[2]*2) +
                             ob.getLocation() +
                             (e[0], e[1], e[2])))
             elif len(ob.data.faces) >= 256: