diff --git a/bld/unit_testers/build-namelist_test.pl b/bld/unit_testers/build-namelist_test.pl
index 06c9bcc361..5fb7b4f39b 100755
--- a/bld/unit_testers/build-namelist_test.pl
+++ b/bld/unit_testers/build-namelist_test.pl
@@ -1359,8 +1359,8 @@ sub cat_and_create_namelistinfile {
                                      namelst=>"fsurdat='build-namelist_test.pl'",
                                      phys=>"clm6_0",
                                    },
-     "hillslope with init_interp"=>{ options=>"-bgc bgc -envxml_dir .",
-                                     namelst=>"use_init_interp=.true.,use_hillslope=.true.",
+     "hillslope with init_interp"=>{ options=>"--res 10x15 --bgc bgc --envxml_dir .",
+                                     namelst=>"use_init_interp=.true.,use_hillslope=.true.,hillslope_file='/dev/null'",
                                      phys=>"clm6_0",
                                    },
                );