# Upgrading

## Upgrading to 0.9

The generator was completely rewritten, so any code with a deep integration to mockery will need evaluating

## Upgrading to 0.8

Since the release of 0.8.0 the following behaviours were altered:

1. The `shouldIgnoreMissing()` behaviour optionally applied to mock objects returned an instance of `\Mockery\Undefined` when methods called did not match a known expectation. Since 0.8.0, this behaviour was switched to returning `null` instead. You can restore the 0.7.2 behavour by using the following:

       $mock = \Mockery::mock('stdClass')->shouldIgnoreMissing()->asUndefined();