diff --git a/postgres/README.md b/postgres/README.md
index d2e70b302..a363af2e7 100644
--- a/postgres/README.md
+++ b/postgres/README.md
@@ -169,7 +169,7 @@ The two easiest ways to get around this:
 
 # How to extend this image
 
-If you would like to do additional initialization in an image derived from this one, add one or more `*.sql` or `*.sh` scripts under `/docker-entrypoint-initdb.d` (creating the directory if necessary). After the entrypoint calls `initdb` to create the default `postgres` user and database, it will run any `*.sql` files and source any `*.sh` scripts found in that directory to do further initialization before starting the service.
+If you would like to do additional initialization in an image derived from this one, add one or more `*.sql`, `*.sql.gz`, or `*.sh` scripts under `/docker-entrypoint-initdb.d` (creating the directory if necessary). After the entrypoint calls `initdb` to create the default `postgres` user and database, it will run any `*.sql` files and source any `*.sh` scripts found in that directory to do further initialization before starting the service.
 
 For example, to add an additional user and database, add the following to `/docker-entrypoint-initdb.d/init-user-db.sh`: