diff --git a/phys/module_bl_ysu.F b/phys/module_bl_ysu.F
index 403532e094..fd071f5d7a 100644
--- a/phys/module_bl_ysu.F
+++ b/phys/module_bl_ysu.F
@@ -353,27 +353,34 @@ subroutine ysu(u3d,v3d,t3d,qv3d,qc3d,qi3d,p3d,p3di,pi3d,                    &
          present(b_v_bep) .and. present(b_t_bep) .and. present(b_q_bep) .and.  &
          present(b_e_bep) .and. present(dlg_bep) .and. present(dl_u_bep) .and. &
          present(sf_bep)  .and. present(vl_bep)  .and. present(frc_urb2d)) then
-         do k = kts, kte
-            do i = its,ite
-               a_u_hv(i,k)  = a_u_bep(i,k,j)
-               a_v_hv(i,k)  = a_v_bep(i,k,j)
-               a_t_hv(i,k)  = a_t_bep(i,k,j)
-               a_q_hv(i,k)  = a_q_bep(i,k,j)
-               a_e_hv(i,k)  = a_e_bep(i,k,j)
-               b_u_hv(i,k)  = b_u_bep(i,k,j)
-               b_v_hv(i,k)  = b_v_bep(i,k,j)
-               b_t_hv(i,k)  = b_t_bep(i,k,j)
-               b_q_hv(i,k)  = b_q_bep(i,k,j)
-               b_e_hv(i,k)  = b_e_bep(i,k,j)
-               dlg_hv(i,k)  = dlg_bep(i,k,j)
-               dl_u_hv(i,k) = dl_u_bep(i,k,j)
-               vlk_hv(i,k) = vl_bep(i,k,j)
-               sfk_hv(i,k)  = sf_bep(i,k,j)
+
+         ! following v4.5 logic to fix access violation
+         if(flag_bep) then
+
+            do k = kts, kte
+               do i = its,ite
+                  a_u_hv(i,k)  = a_u_bep(i,k,j)
+                  a_v_hv(i,k)  = a_v_bep(i,k,j)
+                  a_t_hv(i,k)  = a_t_bep(i,k,j)
+                  a_q_hv(i,k)  = a_q_bep(i,k,j)
+                  a_e_hv(i,k)  = a_e_bep(i,k,j)
+                  b_u_hv(i,k)  = b_u_bep(i,k,j)
+                  b_v_hv(i,k)  = b_v_bep(i,k,j)
+                  b_t_hv(i,k)  = b_t_bep(i,k,j)
+                  b_q_hv(i,k)  = b_q_bep(i,k,j)
+                  b_e_hv(i,k)  = b_e_bep(i,k,j)
+                  dlg_hv(i,k)  = dlg_bep(i,k,j)
+                  dl_u_hv(i,k) = dl_u_bep(i,k,j)
+                  vlk_hv(i,k) = vl_bep(i,k,j)
+                  sfk_hv(i,k)  = sf_bep(i,k,j)
+               enddo
             enddo
-         enddo
-         do i = its, ite
-            frcurb_hv(i) = frc_urb2d(i,j)
-         enddo
+            do i = its, ite
+               frcurb_hv(i) = frc_urb2d(i,j)
+            enddo
+
+         endif
+
       endif
 
       do i = its, ite