diff --git a/driver/fvGFS/fv_nggps_diag.F90 b/driver/fvGFS/fv_nggps_diag.F90
index 01066f18e..07a471c32 100644
--- a/driver/fvGFS/fv_nggps_diag.F90
+++ b/driver/fvGFS/fv_nggps_diag.F90
@@ -514,7 +514,7 @@ subroutine fv_nggps_diag(Atm, zvir, Time)
        do k=1,npzo
          do j=jsco,jeco
            do i=isco,ieco
-             wk(i,j,k) = -Atm(n)%delz(i,j,k)
+             wk(i,j,k) = Atm(n)%delz(i,j,k)
            enddo
          enddo
        enddo