diff --git a/sql/postgres_databases_by_size.sql b/sql/postgres_databases_by_size.sql
index c043db06..87ccb66c 100644
--- a/sql/postgres_databases_by_size.sql
+++ b/sql/postgres_databases_by_size.sql
@@ -14,6 +14,8 @@
 --
 
 -- List PostgreSQL databases by size descending
+--
+-- Tested on PostgreSQL 12.3
 
 SELECT
   datname,