diff --git a/nuopc.runconfig b/nuopc.runconfig
index 23d6a4c..771bb46 100644
--- a/nuopc.runconfig
+++ b/nuopc.runconfig
@@ -286,7 +286,7 @@ CLOCK_attributes::
      history_ymd = -999
      ice_cpl_dt = 99999 #not used
      lnd_cpl_dt = 99999 #not used
-     ocn_cpl_dt = 3600 
+     ocn_cpl_dt = 1800 #ignored (coupling timestep set by nuopc.runseq) unless stop_option=nsteps
      restart_n = 1
      restart_option = nmonths
      restart_ymd = -999