diff --git a/tests/rt.sh b/tests/rt.sh
index cdd1178294..999d413d1b 100755
--- a/tests/rt.sh
+++ b/tests/rt.sh
@@ -1033,7 +1033,7 @@ if [[ "${CREATE_BASELINE}" == false ]] ; then
   fi
 fi
 
-INPUTDATA_ROOT=${INPUTDATA_ROOT:-$DISKNM/NEMSfv3gfs/input-data_20240501}
+INPUTDATA_ROOT=${INPUTDATA_ROOT:-${DISKNM}/NEMSfv3gfs/input-data_20240501}
 INPUTDATA_ROOT_WW3=${INPUTDATA_ROOT}/WW3_input_data_20240214
 INPUTDATA_ROOT_BMIC=${INPUTDATA_ROOT_BMIC:-${DISKNM}/NEMSfv3gfs/BM_IC-20220207}