diff --git a/README.md b/README.md
index b651ecf..d964166 100644
--- a/README.md
+++ b/README.md
@@ -76,12 +76,12 @@ Most variables are the same as in the [official postgres image](https://hub.dock
 | HEALTHCHECK_PORT | Port listening for cron-schedule health check. Defaults to `8080`. |
 | POSTGRES_DB | Comma or space separated list of postgres databases to backup. Required. |
 | POSTGRES_DB_FILE | Alternative to POSTGRES_DB, but with one database per line, for usage with docker secrets. |
-| POSTGRES_EXTRA_OPTS | Additional options for `pg_dump`. Defaults to `-Z9`. |
+| POSTGRES_EXTRA_OPTS | Additional [options](https://www.postgresql.org/docs/12/app-pgdump.html#PG-DUMP-OPTIONS) for `pg_dump` (or `pg_dumpall` [options](https://www.postgresql.org/docs/12/app-pg-dumpall.html#id-1.9.4.13.6) if POSTGRES_CLUSTER is set). Defaults to `-Z9`. |
 | POSTGRES_CLUSTER | Set to `TRUE` in order to use `pg_dumpall` instead. Also set POSTGRES_EXTRA_OPTS to any value or empty since the default value is not compatible with `pg_dumpall`. |
 | POSTGRES_HOST | Postgres connection parameter; postgres host to connect to. Required. |
 | POSTGRES_PASSWORD | Postgres connection parameter; postgres password to connect with. Required. |
 | POSTGRES_PASSWORD_FILE | Alternative to POSTGRES_PASSWORD, for usage with docker secrets. |
-| POSTGRES_PASSFILE_STORE | Alternative to POSTGRES_PASSWORD in [passfile format](https://www.postgresql.org/docs/12/libpq-pgpass.html), for usage with postgres clusters. |
+| POSTGRES_PASSFILE_STORE | Alternative to POSTGRES_PASSWORD in [passfile format](https://www.postgresql.org/docs/12/libpq-pgpass.html#LIBPQ-PGPASS), for usage with postgres clusters. |
 | POSTGRES_PORT | Postgres connection parameter; postgres port to connect to. Defaults to `5432`. |
 | POSTGRES_USER | Postgres connection parameter; postgres user to connect with. Required. |
 | POSTGRES_USER_FILE | Alternative to POSTGRES_USER, for usage with docker secrets. |