diff --git a/cime_config/testdefs/testmods_dirs/clm/_scripts/get_fates_shell_commands_vars.sh b/cime_config/testdefs/testmods_dirs/clm/_scripts/get_fates_shell_commands_vars.sh
index 8a31a6b996..382fb4e53e 100755
--- a/cime_config/testdefs/testmods_dirs/clm/_scripts/get_fates_shell_commands_vars.sh
+++ b/cime_config/testdefs/testmods_dirs/clm/_scripts/get_fates_shell_commands_vars.sh
@@ -4,6 +4,8 @@
 
 CASE=`./xmlquery CASE --value`
 FATESDIR="${SRCROOT}/src/fates"
-FATESPARAMFILE="${SRCROOT}/src/fates/parameter_files/binaries/${CASE}-params.nc"
+FATESPARAMDIR="${SRCROOT}/src/fates/parameter_files/binaries"
+mkdir -p "${FATESPARAMDIR}"
+FATESPARAMFILE="${FATESPARAMDIR}/${CASE}-params.nc"
 
 # No exit status because it should be called in the same shell.