diff --git a/url2markdown/cli.py b/url2markdown/cli.py
index 138342d..c1e0d00 100644
--- a/url2markdown/cli.py
+++ b/url2markdown/cli.py
@@ -7,5 +7,6 @@ def cli():
                         help="The URL of the article to convert to Markdown.",
                         type=str)
     parser.add_argument("--topics", help="A list of comma separated topics.")
+    parser.add_argument("--topics", help="A list of comma separated topics e.g. 'foo,bar'.")
     return parser.parse_args()