diff --git a/src/benthic_calcite.F90 b/src/benthic_calcite.F90
index 515f79e..d1cf4e1 100644
--- a/src/benthic_calcite.F90
+++ b/src/benthic_calcite.F90
@@ -82,13 +82,14 @@ subroutine do_bottom(self,_ARGUMENTS_DO_BOTTOM_)
       _HORIZONTAL_LOOP_BEGIN_
 
          _GET_HORIZONTAL_(self%id_c, bL2c)
-         _GET_(self%id_om_cal, om_cal)
 
          if (self%iswcal==0) then  ! NB select case would be cleaner but makes vectorization impossible for ifort 14
             fdiss = 0._rk
          elseif (self%iswcal==1) then
+            _GET_(self%id_om_cal, om_cal)
             fdiss = (max(1._rk-om_cal,0._rk))**self%ndiss
          else
+            _GET_(self%id_om_cal, om_cal)
             fdiss = max(0._rk,(1._rk-om_cal)/(1._rk-om_cal+self%KcalomX))
          end if