diff --git a/README.md b/README.md
index 2789da90765..f7677f7b45f 100644
--- a/README.md
+++ b/README.md
@@ -217,7 +217,7 @@ When you change them, use `bin/moodle-docker-compose down && bin/moodle-docker-c
| `MOODLE_DOCKER_WWWROOT` | yes | path on your file system | none | The path to the Moodle codebase you intend to test |
| `MOODLE_DOCKER_DB_VERSION` | no | Docker tag - see relevant database page on docker-hub | mysql: 8.0
pgsql: 13
mariadb: 10.7
mssql: 2017-latest
oracle: 21| The database server docker image tag |
| `MOODLE_DOCKER_PHP_VERSION` | no | 8.4, 8.3, 8.2, 8.1, 8.0, 7.4, 7.3, 7.2, 7.1, 7.0, 5.6| 8.2 | The php version to use |
-| `MOODLE_DOCKER_BROWSER` | no | firefox, chrome, firefox:<tag>, chrome:<tag> | firefox:3 | The browser to run Behat against. Supports a colon notation to specify a specific Selenium docker image version to use. e.g. firefox:2.53.1 can be used to run with older versions of Moodle (<3.5) |
+| `MOODLE_DOCKER_BROWSER` | no | firefox, chrome, firefox:<tag>, chrome:<tag> | firefox:4 | The browser to run Behat against. Supports a colon notation to specify a specific Selenium docker image version to use. e.g. firefox:2.53.1 can be used to run with older versions of Moodle (<3.5) |
| `MOODLE_DOCKER_PHPUNIT_EXTERNAL_SERVICES` | no | any value | not set | If set, dependencies for memcached, redis, solr, and openldap are added |
| `MOODLE_DOCKER_BBB_MOCK` | no | any value | not set | If set the BigBlueButton mock image is started and configured |
| `MOODLE_DOCKER_MATRIX_MOCK` | no | any value | not set | If set the Matrix mock image is started and configured |