diff --git a/setup_files b/setup_files
index 25e9fbc..4d89553 100755
--- a/setup_files
+++ b/setup_files
@@ -30,7 +30,8 @@ def parse_arguments():
                         default='combines-pictures',
                         dest='zip',
                         type=str,
-                        help='package result files in zip bundles',
+                        help='''package result files in zip bundles and set a
+                                filename prefix as a string.''',
                         required=False)
     return parser.parse_args()