diff --git a/my_activity.py b/my_activity.py
index c35833bc7..71c0bc2f2 100755
--- a/my_activity.py
+++ b/my_activity.py
@@ -795,7 +795,8 @@ def main():
   output_format_group.add_option(
       '--output-format-heading', metavar='<format>',
       default=u'{heading}:',
-      help='Specifies the format to use when printing headings.')
+      help='Specifies the format to use when printing headings. '
+           'Supports the variable {heading}.')
   output_format_group.add_option(
       '--output-format-no-url', default='{title}',
       help='Specifies the format to use when printing activity without url.')