diff --git a/python/ctsm/site_and_regional/tower_arg_parse.py b/python/ctsm/site_and_regional/tower_arg_parse.py
index 29d04b710a..33b3db2afa 100644
--- a/python/ctsm/site_and_regional/tower_arg_parse.py
+++ b/python/ctsm/site_and_regional/tower_arg_parse.py
@@ -58,7 +58,7 @@ def get_parser(args, description, valid_neon_sites, valid_plumber_sites):
         "--base-case",
         help="""
                 Root Directory of base case build
-                [default: CESMROOT/NEONSITE]
+                [default: %(default)s]
                 """,
         action="store",
         dest="base_case_root",