diff --git a/.github/workflows/php-test.yml b/.github/workflows/php-test.yml
index 3b014ba3e..4757794c5 100644
--- a/.github/workflows/php-test.yml
+++ b/.github/workflows/php-test.yml
@@ -73,6 +73,38 @@ jobs:
         with:
           php-version: ${{ matrix.php }}
 
+      - name: Install PHP dependencies
+        uses: ramsey/composer-install@v2
+        with:
+          composer-options: '--prefer-dist --no-progress --no-interaction --no-scripts'
+
+      # Installs a different PHPUnit version depending on the PHP version we're testing against.
+      #
+      # | WP  / PHP | PHPUnit |
+      # |-----------|---------|
+      # | *   / 7.0 | 6       |
+      # | *   / 7.1 | 7       |
+      # | *   / 7.2 | 8       |
+      # | *   / 7.3 | 9       |
+      # | *   / 7.4 | 9       |
+      # | *   / 8   | 9       |
+      #
+      # See https://make.wordpress.org/core/handbook/references/phpunit-compatibility-and-wordpress-versions/
+      - name: Update PHPUnit
+        run: |
+          if [[ $PHP_VERSION == "7.1"  ]]; then
+            echo "Installing PHPUnit 7.5x"
+            composer require --ignore-platform-reqs --no-interaction --no-scripts phpunit/phpunit:^7.5 --with-dependencies
+          elif [[ $PHP_VERSION == "7.2"  ]]; then
+            echo "Installing PHPUnit 8.5x"
+            composer require --ignore-platform-reqs --no-interaction --no-scripts phpunit/phpunit:^8.5 --with-dependencies
+          else
+            echo "Installing latest version of PHPUnit"
+            composer update --ignore-platform-reqs --no-interaction --no-scripts yoast/phpunit-polyfills --with-dependencies
+          fi
+        env:
+          PHP_VERSION: ${{ matrix.php }}
+
       - name: Setup Node.js (.nvmrc)
         uses: actions/setup-node@v3
         with:
diff --git a/package.json b/package.json
index 36015eeee..f1e2129bb 100644
--- a/package.json
+++ b/package.json
@@ -23,9 +23,7 @@
     "phpstan": "wp-env run tests-cli --env-cwd=wp-content/plugins/plugin-check/ composer run-script phpstan",
     "lint-php": "wp-env run tests-cli --env-cwd=wp-content/plugins/plugin-check/ composer run-script lint",
     "format-php": "wp-env run tests-cli --env-cwd=wp-content/plugins/plugin-check/ composer run-script format",
-    "pretest-php": "wp-env run tests-cli --env-cwd=wp-content/plugins/plugin-check/ composer install --no-interaction",
     "test-php": "wp-env run tests-cli --env-cwd=/var/www/html/wp-content/plugins/plugin-check/ vendor/bin/phpunit --verbose",
-    "pretest-php-coverage": "wp-env run tests-cli --env-cwd=/var/www/html/wp-content/plugins/plugin-check/ composer install --no-interaction",
     "test-php-coverage": "wp-env run tests-cli --env-cwd=/var/www/html/wp-content/plugins/plugin-check/ vendor/bin/phpunit --verbose --coverage-clover build/logs/php-coverage.xml",
     "test-php-multisite": "wp-env run tests-cli --env-cwd=/var/www/html/wp-content/plugins/plugin-check/ vendor/bin/phpunit -c tests/phpunit/multisite.xml --verbose",
     "test-php-multisite-coverage": "wp-env run tests-cli --env-cwd=/var/www/html/wp-content/plugins/plugin-check/ vendor/bin/phpunit -c tests/phpunit/multisite.xml --verbose --coverage-clover build/logs/php-coverage-multisite.xml"