diff --git a/src/eclm/cime_comp_mod.F90 b/src/eclm/cime_comp_mod.F90
index ada3780b31..4324f4b9d7 100644
--- a/src/eclm/cime_comp_mod.F90
+++ b/src/eclm/cime_comp_mod.F90
@@ -669,7 +669,7 @@ subroutine cime_pre_init1(esmf_log_option)
 #ifdef USE_PDAF
       if (present(pdaf_id) .and. present(pdaf_max)) then
         call seq_comm_init(global_comm, driver_comm, NLFileName, pdaf_id=pdaf_id, pdaf_max=pdaf_max)
-        cpl_inst_tag = ''
+        write(cpl_inst_tag,'("_",i4.4)') pdaf_id
       else
         call shr_sys_abort( subname//':: pdaf_id and pdaf_max'// &
           ' have to be present for PDAF' )