diff --git a/db/README.md b/db/README.md
index 7bf559b..751b6bd 100644
--- a/db/README.md
+++ b/db/README.md
@@ -141,6 +141,11 @@ Run the tool from your terminal:
 database_consistency
 ```
 
+
+## postgresql-hll and active_hll
+
+Instructions TBD
+
 ## rails-pg-extras
 
 Specify a custom schema for table_cache_hit