diff --git a/physics/sfc_diff.f b/physics/sfc_diff.f
index d56308b79..b28daef3b 100644
--- a/physics/sfc_diff.f
+++ b/physics/sfc_diff.f
@@ -366,8 +366,6 @@ subroutine sfc_diff_run (im,rvrdm1,eps,epsm1,grav,                &  !intent(in)
               z0max = max(zmin, min(z0,z1(i)))
             endif
 !
-!           ustar_wat(i) = sqrt(grav * z0 / charnock)
-!
 !**  test xubin's new z0
 
 !           ztmax  = z0max