diff --git a/physics/GWD/ugwpv1_gsldrag.F90 b/physics/GWD/ugwpv1_gsldrag.F90
index 426cb17f3..5e180a5e1 100644
--- a/physics/GWD/ugwpv1_gsldrag.F90
+++ b/physics/GWD/ugwpv1_gsldrag.F90
@@ -556,7 +556,8 @@ subroutine ugwpv1_gsldrag_run(me, master, im, levs, ak, bk, ntrac, lonr, dtp,
                  du_osscol, dv_osscol, du_ofdcol, dv_ofdcol,         &
                  slmsk,br1,hpbl, con_g,con_cp,con_rd,con_rv,         &
                  con_fv, con_pi, lonr,                               &
-                 cdmbgwd(1:2),me,master,lprnt,ipr,rdxzb,dx,gwd_opt,  &
+                 cdmbgwd(1:2),alpha_fd,me,master,                    &
+                 lprnt,ipr,rdxzb,dx,gwd_opt,                         &
                  do_gsl_drag_ls_bl,do_gsl_drag_ss,do_gsl_drag_tofd,  &
                  dtend, dtidx, index_of_process_orographic_gwd,      &
                  index_of_temperature, index_of_x_wind,              &