diff --git a/.github/workflows/php-qa.yml b/.github/workflows/php-qa.yml
index 5e4523b..455e3b5 100644
--- a/.github/workflows/php-qa.yml
+++ b/.github/workflows/php-qa.yml
@@ -35,7 +35,9 @@ jobs:
                 php-version: ${{ matrix.php-versions }}
                 ini-values: zend.assertions=1, error_reporting=-1, display_errors=On
                 coverage: ${{ ( matrix.php-versions == '7.4' && 'xdebug' ) || 'none' }}
-                tools: parallel-lint
+                # For running against 'lowest' PHPUnit, Composer < 2.2 is needed due to bug
+                # https://github.com/composer/composer/issues/10387
+                tools: ${{ ( matrix.dependency-versions == 'lowest' && 'parallel-lint, composer:v2.1' ) || 'parallel-lint' }}
 
             - name: Check syntax error in sources
               if: ${{ matrix.dependency-versions == 'highest' }}
@@ -64,6 +66,7 @@ jobs:
 
             - name: Run unit tests (without code coverage)
               if: ${{ matrix.php-versions != '7.4' || matrix.dependency-versions != 'highest' }}
+              timeout-minutes: 15
               run: ./vendor/bin/phpunit
 
             - name: Run unit tests with code coverage