diff --git a/mltb2/data.py b/mltb2/data.py
index 5098369..92c078e 100644
--- a/mltb2/data.py
+++ b/mltb2/data.py
@@ -4,7 +4,11 @@
 # This software is distributed under the terms of the MIT license
 # which is available at https://opensource.org/licenses/MIT
 
-"""Data loading functionality."""
+"""Data loading functionality.
+
+Use pip to install the necessary dependencies for this module:
+``pip install mltb2[data]``
+"""
 
 import os
 from hashlib import sha256