diff --git a/README.md b/README.md
index 79486d6..1cf9ddd 100644
--- a/README.md
+++ b/README.md
@@ -36,5 +36,6 @@ blacklists = ["adult","malware"]
 * Filters for regex urls
 * Reduce memory footprint
 * Code optimisation
+* Use of constant database (CDB) for on-disk store : https://github.com/acg/python-cdb
 * Tests
 * ...