diff --git a/README.md b/README.md
index ed15f94..f0bc4e1 100644
--- a/README.md
+++ b/README.md
@@ -238,6 +238,8 @@ page.
 [Encryption class](https://confluence.atlassian.com/doc/encrypt-database-password-1115674739.html) for the database password.
 Depending on the secret class, the value of `ATL_JDBC_PASSWORD` will differ. Defaults to plaintext. 
 
+**WARNING:** JDBC encryption can only be used with Jira instances that have already been set up.
+
 Starting from 8.6 [AWS SecretsManager](https://link to CAC doc) is supported.
 
 Example: