**Symfony version(s) affected**: 5.1.0 **Description** <!-- A clear and concise description of the problem. --> [`ExpectDeprecationTrait::expectDeprecation()`](https://github.com/symfony/symfony/blob/729e21c65356880bd9488588e726aa8735dcb52f/src/Symfony/Bridge/PhpUnit/ExpectDeprecationTrait.php#L23) conflicts with [`TestCase::expectDeprecation()`](https://github.com/sebastianbergmann/phpunit/blob/57e5e77b62086033528ee1f4063ae03035f57894/src/Framework/TestCase.php#L527), which was introduced in phpunit/phpunit:8.4.0. **How to reproduce** <!-- Code and/or config needed to reproduce the problem. If it's a complex bug, create a "bug reproducer" as explained in: https://symfony.com/doc/current/contributing/code/reproducer.html --> Use `SYMFONY_PHPUNIT_VERSION=8.4.0`. **Possible Solution** <!--- Optional: only if you have suggestions on a fix/reason for the bug --> Update the method name, like suggested at https://github.com/symfony/symfony/pull/35192#issuecomment-584776493.