diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6c1c666dcdf80d965ae2b65d25b19c328e8f3b4f..d1cc1214c1d9120faa109a92f162094bfc2fb537 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -26,7 +26,6 @@ before_script:
 
   # PHP extensions
   - docker-php-ext-install mbstring mysqli intl gd zip bz2
-  - docker-php-ext-enable mbstring mysqli intl gd zip bz2
 
   # Install Composer
   - curl -sS https://getcomposer.org/installer | php
@@ -55,6 +54,7 @@ PHPunit:PHP5.3:MySQL:
   script:
     - phpcs -n
     - phpunit
+  when: manual
   allow_failure: true
 
 PHPunit:PHP5.6:MySQL: