diff --git a/cubids/cubids.py b/cubids/cubids.py
index 8cbb4dc4..b666656a 100644
--- a/cubids/cubids.py
+++ b/cubids/cubids.py
@@ -84,6 +84,8 @@ class CuBIDS(object):
         A data dictionary for TSV outputs.
     use_datalad : :obj:`bool`
         If True, use datalad to track changes to the BIDS dataset.
+    is_longitudinal : :obj:`bool`
+        If True, adds "ses" in filepath.
     """
 
     def __init__(