diff --git a/.travis.yml b/.travis.yml
index bd7316f..4fdf730 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,19 +4,19 @@ dist: trusty
 matrix:
   include:
     - php: 5.6
-      env: DB=MYSQL PHPCS_TEST=1 PHPUNIT_TEST=1
+      env: DB=MYSQL INSTALLER_VERSION=4.0.x-dev PHPCS_TEST=1 PHPUNIT_TEST=1
     - php: 7.0
-      env: DB=PGSQL PHPUNIT_TEST=1
+      env: DB=PGSQL INSTALLER_VERSION=4.1.x-dev PHPUNIT_TEST=1
     - php: 7.1
-      env: DB=MYSQL PHPUNIT_COVERAGE_TEST=1
+      env: DB=MYSQL INSTALLER_VERSION=4.2.x-dev PHPUNIT_COVERAGE_TEST=1
     - php: 7.2
-      env: DB=MYSQL PHPUNIT_TEST=1
+      env: DB=MYSQL INSTALLER_VERSION=4.x-dev PHPUNIT_TEST=1
 
 before_script:
   - phpenv rehash
   - phpenv config-rm xdebug.ini
   - composer validate
-  - composer require silverstripe/installer:4.0.x-dev ezyang/htmlpurifier:* --no-update
+  - composer require silverstripe/installer:"$INSTALLER_VERSION" ezyang/htmlpurifier:* --no-update
   - if [[ $DB == PGSQL ]]; then composer require --no-update silverstripe/postgresql:2.0.x-dev; fi
   - composer install --prefer-dist --no-interaction --no-progress --no-suggest --optimize-autoloader --verbose --profile