diff --git a/src/core_atmosphere/dynamics/mpas_atm_time_integration.F b/src/core_atmosphere/dynamics/mpas_atm_time_integration.F
index 227fbde862..ff6141e08a 100644
--- a/src/core_atmosphere/dynamics/mpas_atm_time_integration.F
+++ b/src/core_atmosphere/dynamics/mpas_atm_time_integration.F
@@ -3961,14 +3961,16 @@ subroutine atm_advance_acoustic_step_work(nCells, nEdges, nCellsSolve, cellStart
          end do
          !$acc end parallel
       else
+         call mpas_timer_start('advance_acoustic_step_3964')
          !$acc parallel default(present)
-         !$acc loop gang worker collapse(2)
+         !$acc loop gang worker vector collapse(2)
          do iCell=cellStart,cellEnd
             do k=1,nVertLevels
                rtheta_pp_old(k,iCell) = rtheta_pp(k,iCell)
             end do
          end do
          !$acc end parallel
+         call mpas_timer_stop('advance_acoustic_step_3964')
       end if
 
 !$OMP BARRIER