diff --git a/requirements.txt b/requirements.txt
index faa7636..6f82337 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 # first list the packages you wish to download from PyPI
 teachbooks # depends on jupyter-book
 
-# Our favourite Sphinx extensions in one line
+# Our favourite Sphinx extensions in one line, replace with individual extensions if you prefer some extensions not to be included (https://github.com/TeachBooks/TeachBooks-Favourites)
 git+https://github.com/TeachBooks/TeachBooks-Favourites
 
 # Now list the packages you want to download directly from GitHub