diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index dbc29c23b7c70df2955425dcb2e073066e6472df..a612f3f847ec014ccabee4f797737ba91525552e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -10,21 +10,23 @@ before_script:
   - apt-get clean
   - apt-get -yqq update
 
-  # instll the required packages for the running CI tests
-  - apt-get -yqqf install zip unzip subversion mysql-client libmysqlclient-dev --fix-missing
+  # install the required packages for the running CI tests
+  - apt-get -yqqf install zip unzip subversion mysql-client default-libmysqlclient-dev --fix-missing
 
   # PHP extensions
   - docker-php-ext-enable mbstring mcrypt mysqli pdo_mysql intl gd zip bz2
 
   # Install Composer
   - curl -sS https://getcomposer.org/installer | php
-  - php composer.phar install
 
   # Set up WordPress tests
   - bash bin/install-wp-tests.sh wordpress_tests root mysql mysql latest true
 
+  # PHPUnit for most builds
+  - php composer.phar global require "phpunit/phpunit=6.1.*"
+
   # Install PHPCS and WPCS
-  - composer global require automattic/vipwpcs
+  - php composer.phar global require automattic/vipwpcs
   - phpcs --config-set installed_paths $HOME/.composer/vendor/wp-coding-standards/wpcs,$HOME/.composer/vendor/automattic/vipwpcs
 
 PHPunit:PHP5.3:MySQL:
@@ -32,7 +34,7 @@ PHPunit:PHP5.3:MySQL:
   services:
     - mysql:5.6
   script:
-    - composer global require "phpunit/phpunit=4.8.*"
+    - php composer.phar global require "phpunit/phpunit=4.8.*"
     - phpcs
     - phpunit
 
@@ -41,7 +43,7 @@ PHPunit:PHP5.6:MySQL:
   services:
     - mysql:5.6
   script:
-    - composer global require "phpunit/phpunit=4.8.*"
+    - php composer.phar global require "phpunit/phpunit=4.8.*"
     - phpcs
     - phpunit
 
@@ -50,7 +52,6 @@ PHPunit:PHP7.0:MySQL:
   services:
     - mysql:5.6
   script:
-    - composer global require "phpunit/phpunit=6.1.*"
     - phpcs
     - phpunit
 
@@ -59,7 +60,6 @@ PHPunit:PHP7.1:MySQL:
   services:
     - mysql:5.6
   script:
-    - composer global require "phpunit/phpunit=6.1.*"
     - phpcs
     - phpunit
 
@@ -68,6 +68,5 @@ PHPunit:PHP7.2:MySQL:
   services:
     - mysql:5.6
   script:
-    - composer global require "phpunit/phpunit=6.1.*"
     - phpcs
     - phpunit